That is quite a bit of swing arm. Just dunes? And if so it wouldn't hurt to have +6 if you plan on doing more mods in the future.
16 tooth sprocket is definitely gonna make it feel weak. Try the 14/41 and see where you wanna go from there. There just isn't enough power to properly turn a 16 tooth sprocket with out a massive rear sprocket.
Pods and T5's typically eat a 27.5 pilot, 280/290 main. Start even fatter and work your way down just to be sure.
If you're doing a cool head, stay away from race gas domes if you do not intend to have the crank trued and welded.