I have an electric 1700psi I bought from WalMart. It really isn't what you would want to use for washing big decks or driveways, but it is fabulous for bikes. It does a great job on cars (especially the wheels) too. Miine is the standup type that you can put soap into, and that part of it sucks. Get a small garden sprayer for that. I had one of the smaller ones, it was a 1300 psi, but it used the same motor. It didn't have the soap dispenser. I thought the bigger one would be better, but its really the same. I would buy that one again if I had to do it all over again. You can't go wrong with it for only $100.00.
For soap I have used everything from simple green to Greased Lightning. The cheapest thing I have found that still works good is to go to walmart and but the very cheapest no name brand of liquid laundry detergant. Add a little water and put it in the garden sprayer. Works great. Purple Power works aabout the best I think.
Rich