All the bearings will interchange with all the spindles. The bolt spacing on the hub is the same, just the bearing and axle diameter are different, so this is a non-issue.
You can swap HICAS and non-HICAS stuff around if you have a press, you just swap the ball joint part onto the non-HICAS spindle. To keep it simple, however, I suggested the R33 spindles. When I said they're the same as Stagea I meant where the shock bolts up. I like simple part swaps better than worrying about pressing out and back in parts that could possibly get messed up in the process, so personally I would just swap the spindles with 33 HICAS ones, and keep the old ones in case these shocks go out and an affordable set of manual Stagea coilovers presented themselves before another set of auto coilovers did.