The Ruger in 45 is on my radar. I may well end up with one soon.
If interested in something in 9mm I will highly recommend this Smith & Wesson.
https://www.smith-wesson.com/product/fpcWeight is just over 5 lbs unloaded/unscoped. It folds in half to just over 16" and will fit in a small pack.
I put a Holosun dot sight on mine and it puts 5 rounds right at 2" at 100 yards. It takes M&P magazines and comes with two 23 round and one 17 round mags. There are storage compartments for 2 spare mags in the stock. With 63 rounds of ammo onboard and the dot sight it's a bit over 8 lbs.
I paid exactly $700 OTD.