if I rent a rig, shall I rent a rig with more horsepower and less day ( 100+ for 1 or 2 days or less) or less power and more days ( 30-60+ Mh/s for 3 -7 days?
which one is better?
I mine coins for ~12 hours, max.
Depends on the network hashrate.
It would be good if you got 100-200MH/s now.