you can just dial down the pressure the HVLP guns can run between 25-45lbs, I use my nail gun compressor all the time for spraying, nail guns run 90-115 with a tank that size I would want to use a water trap with the larger tanks they get alot of condensation, with my small comp. I just make sure to drain it regularly so there is no moisture.

depending on your paint choice, water can give you a condition called fisheye really just a swirl looking pattern, all I spray for modeling is water based paint from www.warbirdcolors.com now, so moisture isn't such a problem Nelsons is also a water clean up paint as well( simmilar to WBC) but auto enamel,and laquer is more sensitive to the moisture issue.

I also use a 50' nail gun hose so it takes a while for any water to make its way to the gun, getting ready to spray a couple of models in the next few weeks a Top Flight P-40 and my 60 size FW-190A8