There are many choices for a person to look for a shop vac. In fact there are local stores and online stores that all sell Shop Vacs. One of the major steps I took was to look at the different reviews and the costs associated with the wet/dry vac. These were some of the most important factors to me. I was also looking into the different specs as well.
One of the areas that I looked at was the max HP it had and the storage capacity. Some people may like the smalle more compact types for quick easy jobs, but usually there was a big mess that needed cleaned or I wanted to be able to use it as a way to blow debree out of the gzarage. For bigger jobs and generally be able to also use the shop vac as a blower, that came in a little larger than the hand help ones.
Ideally it would be a good idea to get a hand help shop vac (wet/dry vac) and a 12-14 gallon shop vac, but not everyone needs both or has the luxury to get both. So I choose the type that would offer the most functions with the largest capacity possible and it has worked out great. There are some really good deals out there when you are in the market of buying a wet/dry vac. One of the best deals I have came across as far as functionality, capacity and horsepower is the VacMaster 14 Gallon, 6.5 Peak HP Vac with Detachable Blower, Green/Black.
This unit has a 14 gallon capacity, a max HP of 6.5 and it also converts over to a blower. This is a great unit for the price. It does not have any reviews yet, but much like some of the other VacMaster products like the VacMaster VBV1412P 14 Gallon, 6.5 Peak HP has 19 reviews with 4 1/2 stars. This is a very close model but the one above is at a lower price. You can be one of the first to provide a shop vac review on this model.
Another great benefit of buying from Amazon is the fact that in most cases you will not pay any shipping or taxes and this makes buying from them an even better bargain.