i prefer using a socket and ratchet.. i like to give them very rusty fasteners a little heat and hammer on a 6 point socket. unless its a very restricted area, i don't like to use a wrench.
SRPC107 is what i use, does what i need it to do. can't recommend a set without knowing what its used for, but that's a good set to start out with for general automotive work.
HF boxes aren't worth much. beat them up, and sell it when you want to upgrade. they're not worth much, so they really depreciate.. but on the opposite side, i bought a brand new snap on box and i can't get even half of it back.
you need one of each set.. sometimes there isn't enough clearance for a ratcheting wrench.. double box end wrenches are also great, they give much more leverage. I'd get the normal combo wrenches.
if you can record some pids the moments before stalling, that would be helpful. is it just suddenly stalling or rpm slowly going down and stalling?
as others have suggested, my first try would be throwing it in neutral and see if it still stalls there.