Avoid Prins and BRC for the same reasons your Landi isn't too clever. Very limited injector options (only the ones that come with it) and, limited software availability (if at all in the case of Prins).
Agreed, I wouldn't recommend either of those especially as a DIY install.
Just to add to that - I expect BRC software is now easily available since Tinleytech are the new BRC supplier and won't be as fussy as the old BRC GB used to be... In the days of BRCGB I believe I was the only installer not to have gone through their 'training' (which BRC installers paid £1000 for) who BRC GB would supply and allow access to their software downloads.. probably because they knew I could sort BRC problems when their local BRC installers couldn't ;-) I know they had a board meeting in which they decided to allow me access even though I hadn't paid lol. Out of the two (BRC / Prins) from a calibration point of view it is far simpler to switch a Prins system from one model vehicle to another provided the Keihin injectors are a good match for the engine spec (BRC a bit more forgiving in this because can work at a wider range of pressures than Prins). I could give you Prins VSI1 software and a valid user key (necessary to make any adjustments) or any of the BRC software (except the latest 'BRC calibration tool', which I have, but which needs a unique activation key which tallies with some unique aspect of each laptop such as I expect it's mac address, so only BRC or TTech can provide the activation key). Both Prins and BRC systems use their own unique interface cables, you can buy clones but they don't always work. For example there are about 7 variants of BRC, the proper BRC cable works on all variants, the clones are usually variant specific. BRC can be a minefield to set up, most variants don't use a runtime vac sensor but need an installer spec vac sensor for initial calibration, some variants use 3 files to setup (firmware, methodolgy and calibration) to suit the vehicle for aspects such as extra injection filtering. There's BRC Sequent, Sequent24, Sequent24MY07, Sequent56, Sequent56MY07, Plug n Drive, Sequent32... Each uses different software
, is setup differently, some are even wired to the car differently (e.g. Seq24 preMY07 cuts the common positive to petrol injectors, no petrol injector breaks as such, just one wire to each petrol injector.. and it's incapable of true sequential operation because it batch fires LPG injectors in blocks of 2).