Need help with deciding on an exhaust

I looked at the exhaust thread and it didn't really answer my questions. So here it goes.

I just recently chipped my 07 Mk5 with the GIAC X chip. My next investment is probably going to be exhaust. I want to do a turbo back exhaust, but not spend too much. I really just want some input on different products. Which piping would be optimal: 2.5'', 2.75'', or 3''? I also want my car to be able to pass smog fine and not have any problems as far as my check engine light going off. Finding a dealer and a place to install is also an issue ( I live near San Diego, CA)

I looked around and found these, if anyone has any more or any input for me, please let me know.

Neuspeed Catback $995.00: http://www.neuspeed.com/products/product_details.asp?app=95|GV&type=5&ltype=ns_euro&p_id=1960

Neuspeed Downpipe $1,195.00: http://www.neuspeed.com/products/product_details.asp?app=95|GV&type=5&ltype=ns_euro&p_id=1947

Milltek $1,450 : http://www.stratmosphere.com/milltek_exhaust_for_vw1.htm

AWE $1,350: http://www.awe-tuning.com/pages/sha...5gj_20t_exhaust.cfm&PPT=Exhaust&IL=mk5exhaust

APR $1,300: http://www.goapr.com/VW/products/apr_exhaust_mkvgti.html

I think those were the 4 I looked at, maybe missed one. I'm comparing AWE and APR right now, since they have dealers near me that would save me time and money on shipping. AWE has 2.5'' piping while APR has 3.0''.