there is alot of threads on this subject, a few are mine lol but i dont car ill share what they tought me
i was faced with the sammme question not too long ago. basicle if the motor you have right now is a sr20de that runns pretty strong somewhat low miles (low miles for a sr20 is somewhere around 100-140k lol) then you go with the fmax kit because it will give you a shitload of power! more than your friend got for sure. but its all about choosing power/or reliability...if you can get both out of your de then go right for it. i couldnt, i have 180k still running ok but i know that if i put a turbo like that on it it would go in a matter of months, and i also wanted to be very upgradible (not saying the usdm or jdm sr20de arnt) but i know that the det engine can handle high boost condititons for a longer period of time without to much stress on the engine. because the usdm or jdm have a 9.5:1 c/r, the sr20det has 8.5:1 with oil spuirters (wich squirts oil to the bottom of your piston) , some say the oil squirters dont matter. (i dont care i would like to know i have them)...
now if you go det swap witch i am going, as far as fabrication and modifications go there are non (some people have to midify a piece on there tranny that hits the cross member on certain engines i believe, its nothing though just alil grinding) the engine swaps right in on the same mounts, it is the same engine as a usdm or jdm sr20 just lower compression. there still is alot of stuff that you need to get though, dont fool yourself like i did!! i just thought ok cool i need engine computer and voila! you could be ghetto and just get ittt in there running but i dont like doing things that way. so ill tell you what my whole systems going to have and what you should get too....
jdm sr20det (u12, u13, avenir, gtir)
clutch (act, CLUTCHNET, stage 2 or 3, i unno theres alot of clutches)
motor mount inserts (ours are very weak!) (es motor mounts)
jwt tuned ecu (jim wolf tech. this is if you want the total plug and play route, i like simple!)
boost ctrl'er (greddy or apex-i, this is not needed just something i want for sure)
turbo timer (greddy or apex-i, another thing nott needed just nice to have
down pipe (jgy )
fmic (issanni, spearco, forge, ect. nottt needed if you keep the top mount on a u12, but there not that efficient, they get heat soak, so its more ike a interwarmer)
fuel pump, (walbro, not neccesarry inless you go big injectors, i think its neccesary though
gauges (look through summit just find some good temp and boost gauges)
totalls to about 3.2k region (work not included),depending on your shopping tech, group buys are pretty cool ive got alot of this stuff on the way as wee speak from group buys.. like i said this is my route there is cheeper and easier ways to get more power, but im going safe and longevity. there will b guys putting down way better quarters than me that only paid 2.5k for there system, and they will argue to the death it runs forever and blah blah, but i dont want to take the chance, and ill like to brag lol.. but i must say it works for most though... pick your route
this is micselanious crap im doing because i dont want to later.
z32 maf or cobra
72lb inj with the three bar program from jwt (heard its a great setup)
fuel rail and fpr
the reason i dont want to do this later is because i dont want to have the hassle of reprogramming my comp everytime i upgrade something like fuel. yea it is going to be over kill for the little t25, but look on the brite side, youve got a system that can support alooott of power, al i need is new turbo and mani and boom i can jump from 230 whp to 350 whp,
ohh yea youll be spinning your tires all over town unless you get some nice deep rims with sticky tires. not needed though just a nice upgrade!