S2000 ebay exhausts / muffler

Hey everyone, was just wondering, I recently bought an S2000 and want to upgrade the exhaust/muffler... i have noticed so many are available on ebay for between $20-$50... are these any good?? are they genuine? any thoughts appreciated!
for example :

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2474495259&category=33636

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2474807826&category=33636

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=2475033203&category=33636

thanks!!!

nope sorry there junky rattle cans. the s2k has nice flowing exhaust so you gotta spend alot to get good upgrade this would either do nothing or hurt your proformance and ruin sound.

ok cool... thanks!

Those will also require the cutting of your stock exhaust pipes, so if you ever want to change it back, it'll require more cutting and welding.

the stock exhausts are already wicked
stay stock and stay with the clean look
y upgrade to something far more inferior?