Bass amp TL;DR?

I'm not new to playing bass by any means, but I've never really had a proper bass amp before. I've always played whatever is in my classroom (music teacher) or gone direct with a modeler for gigs with a small PA speaker (Alto TS408) or in-ears as a monitor. I primarily play musical theater and small jazz/pop gigs, and so far I'm happy with the sounds I'm getting out of my Helix on electric and upright.

That said, I'm curious about putting together an actual amp rig for venues where going direct isn't an option or I need more volume than my little wedge can provide. The problem is I have no idea where to start in terms of speaker size, wattage, ohms, cab/head vs. combo, etc. Any suggestions/articles/jumping off points for building an amp rig?