I have several extractors and grip panels, although I've had those for my semi's long before I got my own Vector smg. For the smg I bought two additional smg barrels, an extra bolt, and an extra trigger/pistol grip assembly, along with a few other assorted pins and springs, like the recoil spring. Parts are pretty readily available, and cheap.
I'm very happy with my Vector smg, you'll be happy with yours too I'm sure.
.22 conversion, mags, Dillon 650, .22 ammo, components, spare parts kit, couple of wood stocks, suppressor, .22 conversion mags, more .22 ammo, more 9mm components...
.22 conversion, mags, Dillon 650, .22 ammo, components, spare parts kit, couple of wood stocks, suppressors (both 9mm and .22), .22 conversion mags, more .22 ammo, more 9mm components...
I'd get at least 1 spare parts kit (I've got 3+). A few more mags wouldn't hurt, they are the right price now. I've got some I paid over $30 each for back then. Ammunition until you reach a 10,000 round minimum. I've got a can and a .45 kit I rarely use. I had a .22 kit, sold it because I never used it. I do have a Doctor Sight on Amphibian's top cover which is priceless. I absolutely love my Vector SMG, it has been trouble free since day one.
Get the sucker to run on .22LR. It will really save you a lot of money. .22LR Cans will really junk up your .22 components quick- they already get fouled quick enough IMO. I stopped using .22 cans on anything FA. YMMV.