Cheap 58k and Pop vs Web-pop vs web

Howdy. I am looking at some cheap isp's (
http://www.freedomlist.com/find.php3?country=166&st=3&areacode=480 ) and
was hopping for some recomondations.

Also I was hopping you could tell me what the between Pop, WebPop, and
Web. Which would I be able to get mozilla mail to wrok with?

Sorry for the noobie questions...