i just bought a 2001 mr2s

i am looking for a good sounding exhaust but not to pricey. but still get some horse power out of it..

There are quiet a few MRS exhausts.

The Apex'i N1 Evo System uses 60mm piping and a 90mm tip.
http://www.apexi-usa.com/products/?id=5507

A quick google search found is much lower than MSRP, in the $560 range.
http://www.gripmotorsports.com/pi~pn~apexi_n1_evo_exhaust-1229.html

The Apex'i WSII uses 60mm piping and a 105mm tip.
http://www.apexi-usa.com/products/?id=5504

Here's a link to the installion PDF for it.
http://www.apexi-usa.com/content/pdf6270.pdf

Both Apex'i's are the rear section only.

5Zigen Makes the Pro-Racer ZZ for the MRS
http://www.5zigenusa.com/english/products/muffler/proracer/zz.html

5Zigen also makes the Pro-Racer Aspec
http://www.5zigenusa.com/english/products/muffler/proracer/aspec.html

5Zigen also makes the BORDER304 SPEED for the MR2
http://www.5zigenusa.com/english/products/muffler/5zigen_sports/border304_speed.html

I'm not sure how much any the the following cost.

RSR also makes an MRs exhaust.

HKS makes the Sport Cat-Back Exhaust System for 00-04 Toyota MR2 Spyder MRS

TRD also made an exhaust, though I'm not sure if it's still available.

Team Moon makes a dual exhaust. There is a stainless version and an aluminized steel version. I've heard it's throaty.

TTE (Toyota Team Europe) Also makes a nice Dual.

Remus makes a nice Duel also.

I've also read a company called Carson makes a Duel similar to the TTE Dual Exhaust.

Good Luck with your search!!