Another.....Bruder Excavator conversion!

[scale hobbies]

Ok, so i've been in the hobby for a long long time and the construction stuff has always intrigued me.

So I've got 2 projects going. I have a King Hauler that I am stripping down to make a dump truck.

I've also just ordered a bruder excavator to convert. So I am going to need some help from you the experts.

I am trying to do this on somewhat of a budget, whatever that is in this hobby.
The rams/screw drives is what's freaking me out, but I am starting from the bottom up.

Pumptech & RockNMayhem i'll be looking to you guys for feedback.

So which servos would be the best for the tracks?
Which servo for the 360 degree rotation of the cab?
Is this spur gear still the #1 choice for the cab http://www3.towerhobbies.com/cgi-bin...?&I=LXAFJE&P=7

Thanks
Matt