http://www.bicperformance.com/products.htm
3" Downpipe with Divorced Wastegate (DDP) -- 369$
Always worth the extra coin to skip the cheap Chinese made ebay products
The purpose of divorced pipe is it gets the turbulent air released from the waste gate out of the main flow which helps improve exhaust flow.
If your worried about legalities they will recirculate the divorced flow back into the main pipe as well.