A little bit of double posting here but I just finished my esc for the turret traverse. Thanks to Darkith's idea I hacked a standard servo into a reversible ESC for the turret traverse mechanism. So that's done. I just need an elevation scheme which I already have in mind.
Here's the converted servo-ESC.
Here's the link for more info
http://www.rcuniverse.com/forum/m_6144490/tm.htm