If you want to stick with MTB-compatible pedals that have some means of load distribution, you might want to have a look at Shimano A-520 "touring" pedals. I have these on two of my bikes and really like them a lot.
I also have three pairs of the Shimano M-520 pedals, and you really can't go wrong with them either. They're about $30 with cleats from Probikekit.com.