The dirt dog chisel plow linked to above would be a good light duty chisel plow to breakup the ground,
then the chisel points could be unbolted and replaced with sweeps to cultivate.
Also a set of disks may be desirable.
You didn't mention the variety of crops you wish to raise.
One problem I have seen several times with roto-tillers is working the soil when the soil moisture is too high.
The upper layer may look well prepared but you can actually create quite a "plow" pack layer at the bottom of the working depth,
this will often seal in the ground permeability and create a very wet patch of ground that does not breath properly.