You will probably be ok for the 5 and other offerings with an RP23 shock. You will be about 18.5 stone with a full camelback & gear on.
I have had trouble as 6'4" 20.5 stone – say 21.5 with gear on. I've tried Orange 5, new spesh enduro, lapierre spicy, cube fritzz, mondraker dune & some others. All of these bikes i need to pump the shock over the reccomended max 300psi (about 360) to get the sag right.
The only one that would suit was the Orang Alpine 160 as the travel ratio means 260psi & I'm good.
As the whole point of this was a lighter bike (current 05 enduro with coil is 36lbs) I decided to stay with the enduro as the alpine was only about 2lbs lighter.
I recon the cutoff between "normal" and fat boys bikes is about 19 stone.