Colbalt Blues are Procambarus alleni (on the rare occasion a LFS will call a young Cherax quadricarinatus that, too). And yes, they can be rather fish aggressive. Excluding individual personalities, that is a rather aggressive species of crayfish in general and falls on the more carnivorous side of the crayfish spectrum. Real nice looking cray, though. But I'd be worried about the bottom dwellers becoming lunch and the angels getting their fins torn by them.
Sounds like a very good sized tank with good set-up. You could have a nice group of Cambarellus in that sized tank (they max at 1.5" as adults), that wouldn't bother the loaches or cories. And you could try a small group of Marmorkrebs (they max at 4-5" as adults) provided you had a means to dispose of the young and you fed them well (this is the species that reproduces parthenogenetically, and though very passive in nature, when not fed properly will attack fish/shrimp/snails/etc). If you could get your hands on Orconectes lancifer (careful, it's illegal to catch, sell, buy in some locations), that'd be a good crayfish to have, too. They're on the smaller side, prefer vegetation and very passive in nature (also, a really nice looking cray).
With the Cambarellus though, I'm slightly worried about the angels for behavioral reasons. I've never kept them personally, but have been told on many occasions that they can be territorial and/or aggressive. If this is true, a small crayfish (the Cambarellus are all dwarf species) might be injured or killed by them. But again, I don't attest to knowing anything about angels... it's just a thought that comes to mind.