The simple answer is all clears, enamels and lacquers, turn yellow eventually. Unfortunately there is nothing you can do to stop it.
The question really is which ones stay clear longer and how yellow they get.
It's the UV rays in sunlight that turn the clear coat yellow, but they will turn yellow even if you don't keep the item in the sun.
I have had good luck with Rustoleum's Crystal Clear enamel (not the gloss clear, but the Crystal Clear).
I would think that two-part finishes would also be very stable, but I have never used them so I don't know for sure.