Hi,
The MJ1200 is fitted to work directly with the Geo via the tubing that is supplied with that reactor. In my opinion, the MJ is a much more reliable pump long term, and stronger as well, especially if you are needing to move quite a bit of effluent through the unit.
The Aqualifter will need to feed via 1/4" tubing, so you would have to reduce it back down. It is not quite as reliable as the MJ, and not as strong either.
Thanks,
Jeremy