I am having a similar project in Finland... (blow through)

Here's my setup:

A12 (A13 pistons)
2 head gaskets for lowering the comp
thicker valve springs

Weber DAT 32 turbo carburettor 150

a15s arnt very common anymore thats why the a12 is being used

as for the oil lines you put a t piece on where the sender sits for the oil feed and you put a fitting onto the oil sump for the return line

if your going to spent your money on a turbo for a a12 you mitgh aswell put a little extra and turbo a a15

my opinion any way

yer i have checked out the manifolds i worried about alternator being on the same side, so talking to a mate who might be able to knock one up to clear. maybe an obvious question but i would like to know were oil comes into a turbo setup i think i got the rest pretty well sused but not much is said were the oil goes. i noticed someone said they tapped it from oil sender, but were does it have to go too. Still learning prob an obvious question

anybody correct me if im wrong but i would say no because you still need a computer and youll pay roughly 1500 for a good computer tune plus you still need to buy a programable computer 500 -1000 alone then injectors and the housing fuel rail ect ect ect $$$

if your prepared to get your hands dirty you should be fine. make sure you get your dizzy regraphed when you done thou cos mine had 45 degrees total advance stock.
i will make a list of exactly what i bought soon and ill put it up

also would direct body injection be better than efi...lyk price wise...i seena bloke who just gota a custom box over them n boosted it from there...lyk kegs setup

blow through sounds betta n let say more modern....i dun lyk the idea of fuel going through the turbo....$2500 is mi budget

efi is alot more expensive but much more powerful and reliable if built correctly if your only doing a a series to be cheap getting efi will blow the budget it would be cheaper for the ca

as for the t25 i was originally going to go for t2 but got a better ihi for about the same price. the t25 would suit an a15 fine in my thoughts, (if your a fter a turbo exhaust manifold i can get them made for $300) ask a few of the members on here about them i run one on mine (sorry for the plug)

yer well some have said the T25??? (off CA correct if wrong) is a bit big but they are easy to come by. im not a burnout king or anything i would just like a bit more power and am tight and dont want to spend heaps. havent we all thought that before, but i got to start somewere.