I too toyed with the idea of the 5-7 for a ccw/hiking buddy. Ended up drifting away from the idea because of logistics (got a Gp100 3" with small grips, instead. A true beauty of a jack-of-all-trades). I have 5 calibers for handgun and I reload for 3 of them. Adding another caliber in the mix just didnt make sense, to me.
Rent a lot of guns, then make a carefully measured choice. For a 1st time CCW auto I'd suggest single stack, .380 or better, moderate in size and weight (so practice doesn't become loathed), good sights for use in low light.
For the revolver side, steel framed (so practice doesn't become loathed), .38special +P or better, the ability to put on a night sight up front.
Good Luck,
Lucky