Which CyanogenMod version should I use on my Transformer Prime?
TF201 isn't supported on CM11, so your choices are to go with official nightlies (which are not stable) of CM10.1 from here or unofficial CM11 from here. Neither of these are stable or officially supported releases.

The Google apps version you should use depends on the CM version you choose to flash. If you're using CM11, use the 20140105 GApps. If you're using CM10.1, use the 20130812 GApps.