HEPA Vacuums

Is anyone out there familiar with HEPA Vacs and using them for abatement or workplace hygiene?

I've been using a typical Ridgid shop vac for all of my vacuuming needs. My house is under destruction for renovation and I also have a number of pets, therefore my shop vac gets used on a daily basis. I use a "hepa material" filter and a bag inside to hopefully keeps dust from escaping. I realize that it's probably not even close to the effectiveness of a true HEPA vac.
I haven't had to use my vac for anything "nasty" until just recently scraping lead paint from an exterior. I was planning on cleaning it, replacing the filters, and running it outside before bringing it back into my home.

I work as a maintenance man and have my house to renovate. I'm working around asbestos, silica, and lead paint enough that I think it would be nice to have a HEPA vac. I'm unfamiliar with the vaccums and the protocols for dealing with hazardous materials collected by them. I'm not planning on doing professional or large scale asbestos or lead abatement, but inevitably you will disturb it if you want to accomplish anything in these spaces.

I tend to be hyper vigilant when it comes to workplace hygiene. Especially at the school where there are kids working and playing while surrounded by asbestos. We perform maintenance on boiler components, acoustical plaster, and tile. The vacuum would at least offer me some peace of mind when we disturb these materials.

I've seen some pretty bad reviews of Ridgid's 400 dollar HEPA vac. Most of them say that it lacks suction. I imagine a good one is going to be close to a $1,000. Does anyone have model recommendations and or guidance on using these tools? Thanks for any help.