Of the engines you mentioned, the Tower 46 would probably be my first choice. But there are several engines that would be a MUCH better choice for a Mojo/Primo than the Tower 46.

If this is your first 3D plane, the 3151 servos will work OK. Several of us in my local club are running them on 6 volts with no problems. It's worth it to get the extra speed and power.

I'm a firm believer in short 2-56 rods with a Z-bend on one end and a DuBro safety clevis on the other. If you need a stiffer pushrod, you can sleeve the 2-56 rod with a carbon tube.

If you want to hear my no-holds-barred opinions about your questions you will have to ask over on the Profile Brotherhood website.