Actually, that's wrong as well (they DON'T stop particles), those cheap hospital mask are used so staff and visitors don't contaminate patients with critters that may be in their exhalation, but you're right about them not having a proper seal (thus not able to stop particulates or filter vapors).
if you're going to wear a respirator, don't layer, wear the Kleenguard NIOSH N95 by itself for a proper seal if you're clean shaven (get rid of those useless surgical masks);
This N95 will not protect you against organic vapors (only dry particles, and that's at a 95% efficiency, which is fine for this hobby);
Your primer and clear coat; oil or water based? The "N" on your N95 stands for NOT oil resistant... (use an R or P if your stuff is oil based);
For organic vapors (OV), you need a BLACK colour coded filtering cartridge that clips on a half-mask, just like in the Amazon link Jefuemon posted(that example has a particulate filter, a P95, clipped on top of both OV cartridges)
This half-mask/cartridge stuff gets complicated and confusing though, and then there's the whole fit-testing issue... so the simpler the better; spraying or painting outside, the nasty stuff gets diluted pretty quickly and the levels are way below threshold limit values, but the strong smell can be scary and annoying. So I recommend you get a disposable respirator that offers protection against particulates, offers some oil resistance (an R or P rating, in case), and helps with nuisance levels of organic vapors (the smell), like in this link:
Some of these places should be able to help you out I'm sure: http://www.infopages...d-clothing.html
Disposable means will usually last for an 8 hour shift, working constantly in a contaminated atmosphere, so don't throw it out after 15 minutes for example, it's still good!