Cheap decent 6x9s for farm truck ?

My 72,

Maybe I should clarify my question if possible..

Do rms and "SPL" rating have a correlation? Would a 200 rms speaker have less "sensitivity" than a 60 rms speaker at the same ohms? And would a 200 rms speaker produce less SPL than a 60 rms speaker?

My understanding of RMS is that it is an average or typical operating wattage which I would think is my first priority after operating at correct ohms. Or should I more be concerned with SPL than RMS?

I am running a low wattage 4 channel setup.

Thank you.