My car is stock height as far as I can tell, with stock trailing arms. And I'm running Sumitomo HTR Z 255/45ZR17's that I got from tirerack.com for $67.00 bucks a piece (cheap tires are for roasting

) ! I've got about 500 miles on um so far, and they're working out great. The car handles like it's on rails, and they ride as good as the Cooper 245/60z15's that were on it when I got it.
Later Jeff
PS Just re-read your post and checked the size's, man your going low, 2 full inches smaller on the diameter than your current tire? That should drop her down a bit. I might have went that low, but I proly couldn't get in my driveway

! Here's a link I used to help figure tire sizes when I was buyin mine.
http://www.discounttire.com/dtcs/infoTireMath.dos
Have a good one!