Travel system recommendations?

Annie
So I think I have FINALLY narrowed down the travel systems I'm interested in...the graco aire4 xt system, or the chicco bravo system. I've read the chicco has the best safety rating, but I've also read that plastic tires aren't as good as rubber tires on a stroller. The chicco has plastic tires, but the graco has the rubber. Has anyone had any experiences with the different tires? Personal preference as to which is better?
I've also read great things about the city mini stroller, but can I attach a chicco keyfit car seat to it? Thanks for the help!