the bolts are 13mm if iirc. i could be wrong on that. just take some metric sockets out there you'll get it.
i say don't get a-1 cardone remanufactured pump because i got one and it was bad, after hearing someone else's testimony to bad pumps from them.
keep your pulley as long as it's not messed up. belt, yes. i got a little grease on my old one or stretched it or something and it squealed pretty bad after i did mine. always helps to have a new belt anyway. security.