As far as driveline lengths, we're not talking about Jeeps. The 10" out of the rear is not going to cause anything. It will actually help offroad by lifting the driveshaft. And the front driveshaft needs to be longer if you ever want a flexy front suspension or more that 3" lift.
Longs are great but not the best thing you can do. I. Personally would do duals and suspension first. Don't nuke the clutch and keep your wheel on terra firma
