Theamazing nate has on on his Gen 3 camry 5SFE.... I was going to get one for my Gen 4 before I had engine troubles. The v6 and the I4 is pretty much the exact same from the cat back.
You might have to have them relocate the hangers, but I doubt it. That exhaust will also fit on the solaras...the new solaras will need some modifaction, but not alot. I would not have any worries about it not fitting. In fact check on the FOR SALE fourm, that same system shows up from time to time.....for about 200-400 dollars cheaper.
The sound is a nice low tone, does not sound ricy....what makes it sound ricy, is when those people remove the resonator.
As for power...you will get some more HP from a cat back...as to be suspected. The whole system is stainless steel, so rusting should not even be on your mind.....the only rusting you MIGHT see is from the bolts...but I would not worry about it
As for having it installed.....just take it to your local shop and have it installed fairly cheap....or if you want, put it on ramps and do it yourself....the point about the hangers, if you did it yourself, you might have to relocate some hangers....but I doubt it.
I hope this helps you out a little.