Yes, there are now lots of water based lacquers, or varnishes if you like. If Crites are a larger operation then they will be forced to use water based products by the EPA. That is why your auto finishes are now water/latex based and not oil.
I think oil is better, but latex varnishes can give good results as long as you seal the wood with an oil based product first. If you don't then the water makes the grain 'pick-up' and you never get a smooth finish.
For his purposes 600 grit will be perfect. Home Depot no longer stock it, but I have found that Walmart do. For furniture finishes I recommend 600 grit for most woods.
Just make sure you remove the drivers before doing ANY cabinet re-finishing.
He does need to know what product was used.