Definitely use water based sprays unless you have a good spray booth with a strong exhaust and a hose ventilated hood over your head. It is possible to create environments that are genuinely deadly for several minutes when spraying large prints with solvent sprays. Lacking a proper painting facility, solvent sprays should be limited to occasional small prints using canned sprays outdoors with your back to the wind and wearing a top quality mask with a 3M 6001 filter cartridge, at least. The problem with solvent spray is, the finish is gorgeous when applied to gloss prints, it dries in minutes, coated glossies are exceedingly scratch resistant, and it is trivial to produce dust free prints even in dirty environments. But it's so-so with matte prints and also with most micro-porous surfaces.
Moving right along, your total application of water based paint should be around 15ml for each square foot of print, at the end of all coats. The most you should put down on a single coat on a vertical print is 5 tor 6 ml per square foot to avoid runs while also keeping the paint from landing on the print in a tacky state, which is bad. 15ml is just enough paint to bring a matte canvas or matte or gloss paper print up to a satin-going-on-gloss finish. Around 20+ml you wind up with a very glossy and extremely scrape resistant surface, but at the expense of somewhat raising d-max and lowering the highlights. If you decide to put down heavy coats, wait until the second coat to avoid runs on the first coat which does not have the advantage of a pre-existing coat to cling to.
I measure the amount of paint applied by weighing the gun before and after each coat with a 7kg digital scale I bought for $10 on ebay. 1 gram is darned close to 1 ml. The model is "SF-400." Very useful tool, also good for applying exactly the right amount of glue when applying prints to Gator. Set the paint flow on your HVLP gun to around 200 ml per minute by spraying water into an empty bottle. When spraying prints move the gun about 1 foot per second over the print, I use an Eno EM-11 clip-on metronome to time myself. I am obsessively quantitative and it serves me well, sometimes.
Be sure to keep the gun from drifting further and further away during each pass, and also avoid speeding up. Those are a strong tendencies for newbys. A distance of 8 to 10 inches is best but feels kind of too close, get over it. if the gun is too far back you will wind up with an ugly, bumpy surface.