I use Cobalt rounds on my Jazz, I've always gotten on with them pretty well (I never really seem to get problems with strings really anyway). Didn't really suit my T-bird new, but after they were old and worn they actually had really sweet tone. Personally I've always preferred my T-bird with a good set of nickel rounds.
Anyways, I've got a 2010/2011 Gibson T-bird, black with a white guard. I've been thinking of getting a 3-ply tort guard for it, I figured you guys would be the best to ask for finding a decent replacement (preferably UK/EU based). The truss rod cover is a POS and I might replace that too, but I'm not too fussed about that one.