Endlies are complete jerks! They eat everything! I've never had that problem with Dels, Oranates or Sens. My Endli was forever swimming around with stuff in his mouth until the recent heater malfunction killed him.
Well you could just see how it goes for now if its working alright. But if you decided to get a 125 the extra 2ft of length would be appreciated im sure. Good luck with you decicsion and post pics!
You will have fish covering the bottom of your tank and an angel alone in a 75 gallon...If that's what you want, that's fine, otherwise, get some fish to occupy the water column.