-I'm not too experienced on servos, so I'm not the best to comment. However, they seem like a good size for a lifter if you're using two.

-The battery looks a but lacking in power, I should think around 12v is right for beetleweights. You also may want to look for one with less capacity, 2000mAh will likely weigh it down, 1200mAh is a nice capacity.

-The transmitter has a failsafe which is always a plus, but seems a tad limited with only 2 channels. With 2, you won't be able to have the lifter and a working drive system. You should look for 3 at least with this design, I'd look for 4 minimum personally.