Without. No need to run a fan in them. There are many ways to modify them to accommodate several clutches. They have worked great any time I've used them. Ridinandreptiles is correct about having an additional thermostat. The wafer style will work but they present a lot of fluctuation if your room is not stable. With that said, I've hatched everything from Burms to GTP in them.
I wouldn't. You would have to get your own thermostat for it, you might as well save the money you would spend on the hovabator and spend it on an old fridge/freezer and convert that into an incubator. It's not that hard, plenty of threads in the DIY section