we went for a mid range system brc on my lads 4.3, iirc prins are more upmarket but not worth it unless you have an expensive big engine.
but it was 3 years ago so things might have changed I would just talk to your local specialist installer see what they recommend for your particular vehicle
if it is a landy and you are anywhere near bridgewater this chap was excellent, he did my old suburban around 20 years ago talked much more sense than any of the significantly fewer installers that were around back then
Think it's single point injection, might be multi point but certainly not direct.
All depends on projects as to whether they are worth doing, some folks say oh you only need it it on a big V8, well if the mileage is going to be mega as in 30,000yr then it will be worth doing.
Been onto local firm, they say fully installed with cert is circa £900.