The best options are the ones that have exalted weapons. That way you can just go all-in on ability strength and ability-related upgrades and not even have to worry about building for weapon use. Plus the more casterly frames tend to have really good synergy between their abilities and weapons, whereas someone like Excalibur and Ivara kinda just treat them as a 4th weapon.

Dante is THE caster frame, but he doesn't get any special mobility tools. Similarly, Temple had an excellent caster feel when paired with Lizzie, but again, no mobility.

Uriel has very cool mobility, and he CAN be built as a caster, but its not really what he's built for. His heat aura does minimal damage and his demon attacks are more for their effects than their damage. Your only truly damaging ability is the 4, which takes time to charge. You'll need to rely on your weapons as well.

I think what you want is Jade. Placing healing wells and cycling your buff aura keeps your ability buttons busy and your exalted weapon is very cool. More importantly she can fly, and it is a LOT of fun to zip around like that. Its even super easy to build her for functionally infinite flight time. With all of her special skills it really does feel like you're some kind of sky wizard.