I have some 5.10 Spires (they were also my first shoe, but I got another pair recently); mostly they're the only pair I've found that suit my oddly-shaped feet. Most important advice? Go into a shop a try a load of pairs on (without socks) - you want a pair that are snug (though they will stretch a little) but not painful.

IME outdoor climbing is much harder on shoes than indoor - my first pair never really went outside, and lasted several years, where this pair have seen quite a bit of trad action and are now looking a bit worn.