The air purifier won't cut it. The dust will be everywhere. Your vacuum cleaner's lifespan will be cut to a couple years unless you're religious about changing all its filters. You'll taste it in the air and in all your food.
They do much better as a pair than alone. I had two males. They will fight for dominance occasionally but also play and sleep near each other. They aren't really affectionate pets but they do bond with their keepers. They like occasional petting and generally don't mind being held for a little while.
Their out of cage time needs to be supervised, because they will chew everything. They're the worst pet rodent there is when it comes to chewing shit they shouldn't. There will be no paint left on any wall corners they have access to, the baseboards will get nibbled all over, any wires will be targeted, etc. They basically need a chinchilla-proofed room for out of cage time. At the very least, anything that could cause them harm should be removed, and know that anything even remotely chewable will be chewed. And that's with supervised out of cage time. If the room hasn't been chinproofed, don't even let them out of your sight.
They're a mixed bag, like most exotic pets. They're cute and often pretty friendly, even if they are rarely cuddly. They need a big cage but their food is inexpensive and easy enough (timothy hay and mazuri chinchilla pellets). Their shit is dry and won't stink unless you slack on the cleaning. Vet bills will be expensive. The dust is by far the worst thing about them, other than that and cage size they're really no harder to keep than guinea pigs.