Is it going to be a 2.5" mandrel-bent stainless steal system? 3"?
I am all for using high-flow cats. I know cats aren't cheap, but the environment is worth it. Are you planning on just one cat? Resonator?
I'd like to know about the piping diameter, the materials used, the quality of the build, the ease of installation, the and the loudness of the exhaust note. I don't want anything really loud, or ricey sounding. I like the sound of the stock exhaust, but wouldn't mind it a bit louder.
Oh yeah, lastly, an increase in actual performance would be nice too...
I would need a lot more specifics before I commit to anything. Personally I think you could built a nice system for near or under $1000, you could save money by going 2.5" instead of 3", since our tiny turbo's won't benefit from the larger size.