Got my darkroom up and running, somewhat. I can tray process my negs, at least. But I need to enlarge these little dudes to poster size, somewhere around 40x50 if not bigger...

beyond buying this paper, what enlarger do I need? 4x5 negs to a 40x50 print. Maybe with some cropping. So, preferably, and with room to spare, something that could enlarge a 4x5 to an 80x100? I'm not kidding around here, though I acknowledge my ignorance might make me sound stupid. I figure aroung 1500 dollars would do the trick but what brand what model, etc?

This is B&W.