restock is listed on the brxl product, about mid august. combos will be rebuilt at that time.
Once Revolver S get into a "steady supply" state I'd suggest a combo of Revolver S plus CC MMP.... Feel free to suggest any more that you want.
There are many other retailers that carry and have stock of the BRXL if you are wanting just the ESC.
13t Crawlmaster or 27t TrailMaster. I would go with Trailmaster and 15/84 gearing for starters.