Actually, I think Swampert is exactly what you're looking for if you want a reliable SR, and he can also support the team, especially with Roar shuffling. Adding Swampert to your team would also complete the "CelePertTran" defensive core.Who is a reliable stealth rocker that doesn't run as a lead and can help the team outside of stealth rock.
I'm creating a new team, that so far consists of
Scarftran - Lead
Vaporeon
Calm Mind Celebi
I don't know how well swampert would work, considering I run vappy.
I don't know how well bronzong would work, since I can't seem to find a use for him other than setting up SR. I don't like screens.
I'm considering Aggron, but I've heard he doesn't fare well in OU.
Swampert and Vappy are actually quite good together as well, since Swampert is neutral to Water and Vaporeon absorbs it (as well as Grass Knots aimed at Pert) and Swampert can absorb the Electric attacks in return.