IMHO, Scubapro is the way to go (especially since you dive in warm water), with Apeks being a close second. A MK2/390/190 (or even another 390) combo is cost effective and will serve you well for many years to come. I'm not sure why you're not wanting a piston-based 1st stage until later. I could see if you were diving NE waters like I am, but you're in cave country.
It takes practice. I'm still working on it myself. Try using slightly bigger diameter snaps if need be, especially if using gloves.
Use the standard stuff. Aren't the HM rings 90* bent? Entanglement city. Also, what happens if you "break a d-ring" at the dive site and have a friend loan you a spare? Uniformity is the name of the game my friend, uniformity.
I'm a pretty big/strong guy myself, Perrone, but I'll be damned if I'm going to throw my back out putting doubles on. GI3 can do it all he wants, I'm using a table/lift-gate.