What's the current rule in Ascension for adding monster HD instead of class levels? Adding, say, Dragon or Outsider HD will give you full BAB and save progression instead of epic BAB and epic save progression. Sure, you'll get less class features and feats (and by extension esoteric abilities), but I'm sure melee-fighter types will enjoy the full BAB. Full good save progression is very nice too.
Both Dragon and Outsider HD get lots of skill points though (6 + Int and 8 + Int respectively), and they'll be going to waste with things like Omnicompetent and Maven. Dragon's d12 HD is going to be wasted too with the divine HD size upgrades.