Dr,
First you must decide whether you want a 12v or 230v. There is a major difference in power between the two.
If you park on the road & dont have access to a mains power point, get the black&dekker vacuum with hose. I have been using for a long time & it does well. It does not have a blower. If fact, you wont find any vacuum in 12v with blower
If you have mains access, get an eureka forbes trolley type vacuum. I use these for household cleaning & to vacuum out the bed mattress once in a while (i am asthmatic ). It does that nicely
Ameyam