Impossible. Boost runs on the native Sprint network. So there is no roaming. No Verizon. You'll have to find a Verizon prepaid MVNO or go to Verizon if you want the Verizon network. You cannot have both.
If Sprint, AT&T, and T-mobile don't work well in your area then also stay away from Straight Talk. That large green coverage map they put over their display phones is for the "dumb" phones that operate on the Verizon network. Straight Talk is a sister company of TracFone, Net10, and the likes. So their "dumb" phones work the same.
Also I believe the Prevail just all-around sucks. My Evo Design gets much better signal than it ever did. But if Sprint really sucks in your area then you should find another provider. Because Boost, Virgin mobile, part of Straight Talk & Net10, and any other MVNO that runs on Sprint will have the same signal.