A few assumptions : I used the scout class weights and a 50kg thrust engine (small) for burn times. (uses 1/6 kg/sec) then about 8 1.5 kg thrust landing jets and a 1 km fall to the surface. probably more like 2kg and 1 kg in 4 pairs giving 1 2 or 3 kg of thrust per station plus pulse modulation.
Lunar transit time is based on a homan transfer (wrong with 3 bodies but...) and the lunar orbit being 28days. figure transfer orbit is about 1/2 the semimajor axis (a) of moon and keplers 3rd says period^2 is proportional to a^3 so tranferr orbital period is almost 10 days, halfway was 4.9 days
The idea of self tracking the vehicle with GPS is an idea that was kicked around for a while. The availability of a chipset that does all the analog work for about $400 makes is really easy. This would only require occasional data back and forth to the earth station.