i record everything through m-audio's mobilepre usb-based preamp. it's fantastic. assuming that you've got something like guitar rig on your system to do the effects, it's your best choice. if you don't have a software-based amp modeler, you're going to have to talk to someone else - i don't know much about hardware in the guitar department.
as for microphones, you just want a condenser mic. since the preamp supports phantom power (required for condensers), just get a mic with good reviews. i use a cheapie i bought from zzounds for about 70$, but you can find other good deals too. avoid the mics that plug directly into your usb port, since you can't upgrade down the line.