Thank you all for the great tips and advice! Sorry for the late reply, but it was busy week at work this week, and I haven't had time until now to get back to the Bowyer's Bench.
Really, you all have given me much to consider and many options.
I went with the Sharpe Finex FX1000, and upgraded my compressor to a 2 HP 10 gallon California Air Systems air compressor, which should be a LOT more quiet than my little pancake compressor I've used for odd jobs around the house and shop.
It looks like I will get to spray the bow in two weeks, since I will be away through next weekend working out of town. We've had so much rain, lately (which is great), but I hope for a dry weekend in two weeks.
Roy, how long do you wait between coats of Thunderbird? The instructions say 3 hours between coats, so I'm guessing that means cleaning the gun after each coat? What about the finish in the gun's cup? Will that keep throughout the day, or does one need to mixup small batches for each coat?
I bought a 3M PPS system, which seems like it will make mixing and cleanup a bit easier, as it replaces the gun's cup, and uses disposable liners and lids. The system seems slick, but we'll see. I'll report back after I spray the bow in two weeks, hopefully.