You seem to have misspelled "vector's".
@mike223 For the avoidance of doubt you only need one RIF. As long as you keep it maintained then it's going to be reliable enough for you to enjoy the game on a regular basis.
Of course, if you want more than one then that's fine too.
Full disclosure - I have three M4's and a MK12 (which is basically an M4 in a frilly dress), three M14's (one long, one short and one in a frilly dress - ie an EBR), two MP5s, a SCAR-L, a G3, an M249 (when my back holds out), a MAC 11, a breacher shotty and an HK45. I used to have an AK but the ergonomics didn't work for me. Logistics isn't an issue if you're prepared to put in a bit of thought or just have a few rigs/placards. Lately I'm favouring the old school stuff that will hold just about any mags.
If you have space in your house and your bank balance can stand it, fill your boots. Just don't get into debt to play toy guns. Be honest with yourself and keep what you like unless you need to either make space or money.