"True" HEPA Vacuum for Post-Remediation & Small Particle Cleaning (under $500?)

We're looking for a vacuum to handle post mold remediation and Small Particle Cleaning (SPC). We've been advised to get a "true" HEPA vacuum. Getting so confused about them and HEPA filter ones...argh! Anyways, do you have a recommendation under $500 or just around there?

Thoughts on this one- RIGID 14 gallon professional with HEPA filtration. I'm assuming this is not a "true" HEPA. Thank you!