Tinley Tech are a good supplier, I wouldn't say anything against them, they have a great reputation and rightfully so. For an amateur they would make a good choice as they are prepared to give amateurs tech support at basic level as well as pros at higher level.
There are other suppliers, some might have lower prices, not sure on how an amateur doing their first install on a techy vehicle would rate all such company's tech support though....
Always surprising when people (particularly none installers) that frequent the forum only advise one supplier / one route when they are full in the knowledge of another option that might be of interest to people who intend to convert their own vehicle... There are a minority of installers, like myself, that sell DIY kits to people such as yourself as a side-line. Some of us are really good installers and will have converted many examples of the same vehicle that a kit buyer intends to convert, some perhaps very recently.. Can provide very specific and detailed install tips / info. Support is taken to the next level - for DIY kit customers I am available to phone (and email) at any time not just within office hours, have personally converted all the Land/Range Rover models recently, will give advice on specifics such as how to fabricate brackets (no kit ever comes with all parts supplied, there will always be some fabrication to do), component mounting, pipe routing, wiring, etc, explained in detail.
Some of my biggest DIY kit selling points are that if customers struggle to complete the install they can bring the vehicle here for completion or maybe just for minor aspects putting right (for which I wouldn't charge). Probably not a bad idea to come after the conversion anyway as I do a safety inspection and very thorough calibration all for free too...
Would be able to supply a map for any system I supplied for one of these vehicles but it's always best to fine tune maps, particularly on these vehicles which need a petrol return fitting - The flow of the petrol return will affect the petrol pressure reading, which in turn will affect how the LPG system should be mapped because the petrol ECU has a closed loop system for adapting to petrol pressure too. It is difficult to accurately say what the fuel pressure will read with the petrol return fitted, after all if the vehicle manufacturer were completely confident that the petrol system could run with a constant and specific petrol pressure this would negate the need for the closed loop system regards petrol pressure. The return is needed because running on LPG the petrol system still believes the engine is running on petrol, the petrol pump must still be running but without petrol injectors operational - the petrol pressure rises without a return fitted making LPG system calibration very difficult and in any case generating error codes when the petrol system interprets the high pressure reading as a fault with the petrol system.
Going back a few years you could just say 'A Landirenzo X system' and everyone would know what parts that system would comprise. These days the same isn't often true - If you say 'King system', that would only tell us the name on the sticker on the ECU, it wouldn't tell us which reducer or injectors you had, while the 'King' branded ECU would actually be manufactured by AEB. If you say 'Emer system', then would expect the same AEB ECU as you would fit with the King system (this time wearing an Emer sticker but this ECU won't work with as wide a range of injectors as the King ECU), would expect an Emer reducer, would expect the injectors to wear an Emer badge but actually they would be Valtek type 34 injectors.
It sometimes works out cheaper for pro installers to buy LPG systems in component form (ECU's, injectors, reducers, etc, not necessarily from the same supplier) or to buy complete kits but shelve parts that are not best suited to the vehicle in question (but which will at some point suit another vehicle) and buy extra parts for the vehicle in question (later, if said installer has suitable injectors and reducer on the shelf for another vehicle, the installer only needs buy an ECU to make another complete system, nothing gets wasted but on the whole the installer doesn't spend as much in parts over a period). Sometimes better results can be had if you don't limit yourself to the component lists of single name systems. The above, in addition to bulk buying, trade and loyalty type discounts, can be an area where installers like myself can make a mark-up when selling DIY kits to people like yourself - making a profit without increasing the kit cost to the DIY customer or at least not by much, but at the same time the DIYer gets exceptional support with service that might usually cost extra included for free - particularly relevant if there comes a point where you find you'd like to take it to a pro or supplier for some fettling, checking or just calibration.
A wide range of ECU's, injectors, reducers are appropriate for this model and most combinations of these components (but not all combinations) would work well.
Besides the usual list (above) of LPG system components, in addition to the tank and filler you will need a valve lube system (choice of electronic or vacuum type, choice of brands) and a solenoid controlled fuel return with around 0.8mm jet (various ways of accomplishing that). Seemingly not included in the kit in the link provided by Gilbert above.
If interested just get in touch, email and phone at the bottom of all my posts.
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
2 miles A1, 8 miles M62, http://www.Lpgc.co.uk