Honda GX690 or iGX800

The difference is only 2 maybe 3 good days of cleaning…Get the most reliable system you can. If you’re doing lots of concrete a little bit of PSI may let you go a bit faster…and maybe allow you to do another job that day?

gear or belt fan?

This is a very debatable subject. We have both. Pluses and minuses to both. Build quality of either plays a big part of your overall decision.