I just got this:
https://www.homedepot.com/p/RIDGID-...-Filter-Hose-and-Accessories-WD4070/202077241
For dragging around garage its nice, never tips over cause its low and wide.
Comes with a bag and regular filter.
I really like having a bag, keeps the filter clean and the shop vac clean, if I'm doing a lot of dusty or large volume dirt work, I use this:
https://www.homedepot.com/p/Dustopp...ia-with-2-5-in-Hose-36-in-Long-HD12/302643445
stops the bag from filling up fast and keeps the fine dust out.
I just recently re-did my detached garage, added drywall and grinded the floor for epoxy, with the dust stopper and new vacuum it worked great. I ended up with 2 5 gal buckets of pure concrete dust when I was done. Between dust stopper, the bag, and filter I never once saw any dust make it through and get blown out.
I never use the wet function, so buying a big huge one has never made sense to me. Look at the motor specs, I made sure to get one with the highest amps, as I wanted the most sucking power, shop-vac usually lists the CFM and sealed pressure height on their website too, makes it easy to find one for your needs.
If you want a really small once, since you sounds like you might be transporting it, I jsut got this one for the house and cars, its tiny but has some serious power:
http://www.shopvac.com/product/shop...k-hp-all-around-ez-wet-dry-vac-catnum:5895400