HPI put a 36oz/in servo in the WR8????? Seriously? What a waste of effort! Why not just use a rubber band? HPI has NOT been making the greatest decisions of late...... I'm just glad they did not end up with the OFNA brand. They would've ruined it.

Can't really go wrong with Hitec. Any servo listed as "standard size" should fit. Then just pick the one with the amount of torque you want. Start with the stock servo's torque rating, then double it. Or, triple it, depending on your budget.