I have finally settled on a rim that I like on the ES. The rims are 17 * 7 with an offset of +45. Will these fit a 3rd Gen ES (97-01) without a problem? Also what tyre size is recommended (i.e. width)?

 

yes, those should fit fine. In terms of tires, i currently am running a 225/45/17 [on an 7.5" wide]
* i am biased, the +45 may stick out a little too much for my tastes in the front. I have ran a ET +40 on two different sets of rims [18" & 17"] The rear clears the strut housing and it sits in the quarter panel a little, past the lip. IN the front the similar story although it sits a little closer to the lip.

So i suggest getting a 215/45/17. With that tire size i have pretty much the same ride quality as before with my 215/55R16! The ride is not harsher or anything.

This is the BEST tool to determine ideal tire sizes!