Deagle Gold is only the regular deagle with 3 more bullets, that could be helpful on the fields, but understand that you wouldn't need a secondary if you primary could sustain you on the fields. Having an M4 or an AK are great guns, but even better when you have 8 more bullets and less recoil! Don't get the m4-c, because it get's boring after a while and you can get that anytime through crates, but you can't always get a gold gun
So... If you don't have a good primary, get the deagle, if not, m4gold/akgold is your best choice, don't get the m4-c.