#2
You could hire a luthier to route and install the floating trem and locking nut. So, to answer your question, yes, but it might be pricey.
Gear:
Ibanez RG7321 Seven String
Epiphone Iommi Signature SG
Digitech Scott Ian Black 13
VOX Valvetronix AD100VTH
Laney 4x12 w/Celestion 50s
#3
Buy one that already has a floating trem
ESP Eclipse-II VTB (With 18v Mod)
Randall RG75
Tapco Mix60
New Zealand
#4
Honestly, get another guitar. It will cost a lot and your guitar will be out of commission for a long time.

BTW, its easier to go from a guitar with a floating bridge to one that is non-floating, then trying to do what you are doing.