You mentioned Warlock, so how about either Warlock//Fighter or Warlock//Ranger? That'll get you a full BAB, a couple of good saves, eldritch blast all day, several skills and abilities, and some feats (if you go fighter) or an animal companion (if you go ranger).

Also, if you do that, you might want to look at the eldritch glaive (I think) invocation that lets you melee full attack with your eldritch blast (maybe with some Power Attack fun, if you can you both at the same time).