Look on nasioc for a vf52 or bnr turbo if you want a deal. Otherwise your best off getting something new. The only Subaru turbo you can get is the 52. You can go to blouch for the 330/380/420 turbos that fit our cars as well or BNR.
If you bought an aftermarket intercooler of the Process west styleing that has regular turbo pressure hoses you can open yourself up to use any turbo that fits a subaru from 03 onwards.
Vf48 comes on the sti. It won't fit an 09+ without going to an aftermarket intercooler.
You'll need to request access race tuner through cobb. Do a google search for the request form. Fill the electronic online form out andthey will send it to you to download. Once you install it you'llhave to send me a copy through a data serveror msn messenger or skype so I canuse the same one they sent you. Then you'll just datalog.
if you do a stage two tune, cobb has already deleted the codes for uncatted pipes. So either one is fine. Unless you do a real emissions test and not just a light check, then you would need a cat.
A vf52 will work with no major changes. You can keep the stock intercooler as well. You'd have to run it at lower boost like you said but it'd be better than the td04. They didnt come on sti's though. Im assuming your friend has a wrx not the sti model.
I can help you with the tune if you want.
Sways and springs accomplish two different tasks, although the springs help a little bit in the swaying department as well.
Sway bars just keep body roll out. regular straight line bumps and jumps will not be affected in any way. That's great for curvy roads and on ramps and such.
The springs stiffen everything up and make the car more compsed over all, but alone won't take too much body roll away. They will help reduce roll some but not even close to what the sways will do. The springs will get rid of that wafting floating feeling when you're cruising down the road.
So the question then becomes which would you prefer to get rid of most?
Also, a spring swap will need an alignment and if you're not comfortable doing it yourself someone to install them.
The swaybars are a fairly easy swap taking just a few minutes but you'll need some endlinks to go with them cause the subaru ones are way too weak to handle the stiff bars for any long period of time.
I suppose it just depends on how much you would like to spend and what's most important to get done first. To make the car more fun on highways and keeping up speed I would just pick up an Accessport and a CNT downpipe and go ahead and flash stage 2. Really helps out the top end compared to the weak stock tune and pretty much maxxes out your engine performance right away. Then do some suspension and brakes. Cosmetic upgrades are always what I do last since I don't see them as beneficial in any practical way. Looking pretty never compares to having a great performing car in my mind. It's up to you though. Have fun with it.
Either way is good. The AP is easier to carry around than a laptop and comes with some base tunes. The etune is cheaper to buy but then you need to pay someone to tune for you unless you know someone or can do it for free yourself. With the AP you still can do custom tunes and sure as many on there as you like for different situations and cobb sends you the tuning program for free if you shoot em an email. Stage one on the cobb is a huge improvement over stock. Stage two is a decent bump above that but once you have the downpipe you can get some custom tunes which I can help you with if you want.
I like the ap myself. Just up to you which direction you want to take.