As for the OP's Question, As Lee asked, whats your budget rb4no?
If you keep your eyes peeled and check ebay/gumtree daily, your bound to get a decent machine with the specs your after. Depending on how often you use it, diesle is probably better, though ive found a lot of drain jetters are petrol.
As you can see from me and lees discussion, if you go for a high flow machine, you can use it for all sorts of things, and it will make your job easier. just make sure you have the water supply to keep up with it.
Most jetters are briggs & stratton/lombardini/honda or one starting Kobuta.. go for a decent name brand thats been well serviced and you cant go wrong. Interpump are the standard, but i know the speck pumps are heavy duty, or cat pumps are good too.