Fast. Cheap. Reliable.

You can't have all three and the middle one is locked in by your own admission.

People without the money to pay to do things right from the start and then try to make twice the power the engine was originaly released with (or more) is the reason this platform has its poor reputation for reliability and proper modifications.

Given you state yourself as "poor", I'd suggest you keep to 300 and under, a simple 16g with supports on stock internals will last longer IF you keep up with regular maintenance and don't push your tune. The fact is, many go-fast parts are used, and those used parts have been in service for the better part of three decades, so they have less to give before they give themselves.

What other 400-500hp AWD cars have you had? If none, how about 300-400? If also none, I'd suggest you crawl before you run and build a reliable e3 16g tooter, as they are a great street machine that won't break the bank. At 500, it's a whole world of shit that needs to be bankrolled well.

Sites that support our platform are listed at the bottom of the page. They are our SUPPORTING VENDORS, so you should try to give them business. If used parts are ok, keep an eye out for them in the classifieds on here. Congratulations on the recent purchase and glad to have you on the forum!
Marty