So you have a Forza that can handle significant amounts of oil. You don't want to mess with the cover since you feel it has its place as is. You also have a sanded Ride that is your benchmark ball. You want something that is stronger than the Ride and weaker than the Forza and you want something with length to get through the heads. I hope I am understanding you correctly.
The Forza is one of the earliest and smoothest balls I have seen. It is also pretty strong. The Ride (sanded) is significantly weaker than the Forza. Having it sanded (not sure to what surface) will probably make it stronger and of course earlier and smoother. If all you wanted was more length to compliment the Ride, I would almost suggest another Ride with OOB and perhaps a different drill.
But I like to go to a stronger ball when I have to move in. It will ensure I have enough ball to make the turn. Too many times I see bowlers go to a weaker ball that puts them back where they were on the lane. Unfortunately, you have just depleted all of the oil there and that line will not last long.
So I would think something in between the strength of the Forza and Ride. If you are interested in Motiv, I think the Venom Cobra or Venom Shock with some surface adjustments would be great. If you are looking at Storm, then I feel the original HyRoad or the Match Pearl, depending on how much stronger you want to go.
As stated above, I would be weary of traditional skid/snap balls like the HyRoad Pearl or the Sky Rocket or even the IQ Tour 30 from Storm or the Paranoia or Octane Burn from Motiv. I feel the shape will be significantly different than what you are used to and might give you some problems with control.