I'd recommend using the VTS and a Stabilizer.
The Maximizer kit works great if you can install it, otherwise just go with the drilled valve and have your hammer lightened.
The magic fingers detente is used on Warsensor guns so, yes you can get those from warsensor. You can go remote or tank on-gun but I'd recommend using the tank on the gun because real men have heavy guns.
I'd go with the Magnum body but use normal screws, not the thumb screws. The normal screws are just easier to tighten down correctly. And remember to loc-tite all the screws down if you don't see yourself disassembling anything. VMs can literally shake themselves apart. After every game with my VM I had to re-tighten half the screws.
"There's nary a beast that can outrun a greased-up scotsman!" - Willie
"What makes a VM so charming is that you can chop down small trees with it" - Jaan