I don't think he comes on here all that often now, but you could do worse than email BIGFLYINGROB, he's switched to "Group A" now, but is a long term microlight pilot who would make you look quite small.
He used to have an MW6T (horrible aeroplane in my opinion, but basically safe) but was an instructor and check pilot at one point so should be able to tell you what he fits, or doesn't of a reasonable selection of microlight types.
You could also try contacting Flylight at Sywell -Paul Dewhurst, their CFI is I think a bit over 6ft3", and they also usually have some fairly young FIs there who haven't been infected by middle-aged spread, so may be well suited to help you out with the differences training.
G