RE: Futaba Skyport 4 channel radio
That's the radio I have and no, it doesn't have any mixing at all. No adjustments other than trim. You can buy a 'mixer' that plugs in between your Rx and your two servos and the chips on board do the mixing automatically for you, but that will set you back another $15 or so.
Futaba has a 4 channel computer radio that would more likely suit you if you are on a budget. If you have some more cash and know you'll be in the hobby for a while, the step up to a 6 channel computer radio isn't a bad idea.
www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXKSB5**&P=7