Hello i personally have a 2000 Ford mustang V6 with a Magnaflow catback exaust system. This exaust system makes my v6 sound like a v8 easily. My system has the reverse effect then what you were talking about, when my car idels it just a soft rumble from the exaust, But the second you hit that throttle oh my goodness you would think something just swaped your v6 with a v8. Magnaflow Dual Exhaust Catback System (99-04 V6) at AmericanMuscle.com - Free Shipping!
This is where i got my system from. It all depends on what company you trust the most and what kind of quality the company will send you. Americanmuscle.com i trust because every aftermarket product i have bought i have purchased through AM.com Magnaflow Cat-Back System - 1999-2004 Mustang
This is the one i saw from hillbank that was cheaper.
(I didnt see this one until a few days ago, i have had mine for 3 years now)
They definetly look a little different setup wise goes. I cant vouche for the hillbank exaust because i havent seen or heard one before but the AM.com definetly a sound you will be looking for.