What ďproblemĒ are you trying to solve going to the 200/55? Itís best to answer this question before tackling which wheel to get.
New hoops are a good idea with the new wheels, but I tend to think itís best to make as few changes as possible at one time to make any post upgrade troubleshooting just a little easier.
If youíre upgrading wheels for the handling benefit and weight savings, how much of that will you give up going to the 200 rear and 6.25 wheel? Will the change alter the handling characteristics of the bike ( this is a rhetorical question ) and in what way(s)?
I went with the 6Ē and 190/55 rear. Iím happy with the results.