Well I'm looking into buying a good amp probably pretty soon but I have a couple questions first. First of all, what would you recommend, buying a combo amp or the head and cabinet separate? Second, assuming the same wattage, are more speakers better in a cabinet? I mean would two 10's be better than a 15, and 4 8's better than 2 10's? And finally, I don't have a lot of money so I would like to buy used but is it safe to buy from eBay when you can't try it out first and you have no warranty?