The HF sprayer I use is a bottom syphon feed. It wasn't very expensive, or I wouldn't have bought it. I do use a compressor that has a little air dryer thingy that helps suck off moisture and it also gives a constant pressure for use. It works great and cleanup is easy.
The sprayer I use is a Central Pneumatic make (probably HF generic name brand at the time), 20 fl. oz., high volume, low pressure, gravity feed, top fill, 40 psi. I'm sure it wasn't very expensive, or I wouldn't have bought it and probably thought I might end up throwing it away. It works great, cleanup is easy, I'd guess I've had it for 10 or 12 years and it's going strong. I also use an air compressor that has a constant pressure setting for tools and it has an inline air dryer on it to help keep moisture out of the mix.
I don't know what you are painting, but I'd suggest ordering at least a case of rattle can paint also to use for the parts you need to hit, but don't want to break out the air sprayer. Also I'd err on the side of ordering more paint than you think you need, just in case. I have some of the red primer and regular paint that are @ 8 years old and they work like brand new. I go thru a lot of rattle cans doing touch up, little parts, etc.