I had the Turboxs stage 2 Setup and I liked it but if your on a budget this is what I would do.

I would get a manual boost controller and exhaust mods. Then get an uppipe. You can run low to mid 13s with these mods without any engine management. I know a lot of guys with just exhaust mods and boost controllers and they are running fast times at the track and haven' t had any reliability issuses. I drove around for about 6 mouths with a mbc and exhaust mods. My WRX ran great with this basic setup.

If your going to move up to a larger turbo, fuel injectors, and fuel pump then I would invest in some sort of engine management/chip.