My 5 gallon Home Depot compressor does not have the CFM for the HVLP gun, so am I SOL. The compressor is 6.4 and the guns need around 12. Is there anyway around this other than a 1,000 dollar compressor.
Yes.
With careful planning and execution, your current compressor may be adequate for everything but the wings and fuselage. The control surfaces, cowl, wheel pants, tips, HS, VS, etc. are all relatively small and shouldn't require crazy amounts of air.
There are a couple of ways to do the bigger pieces. One - add a supplemental tank for extra storage capacity. Two - add a second compressor to run in parallel with your existing compressor.
With the supplemental tank (from Harbor Freight, Amazon, etc), you plumb it in alongside your current tank to add storage capacity to your system so you can spray longer before the pressure drops below whatever level you need to spray effectively.
Then, when you paint, paint the top surface of the wing, allow the system to refill while you flip the wing, spray the bottom, wait, lather, rinse, repeat. Applying a coat of paint to one side of an RV-sized wing isn't a killer.
Alternately, buy or borrow another "small" compressor to run in parallel with your existing compressor.
There are other workarounds (like masking to allow you to paint a wing or fuse in sections), but the two suggestions I laid out are the ones I'd feel most comfortable with.