Lovebums large wraps are pretty big and Maggie will do xlarge to custom order I think too. We had problems with eczema and the worst reaction of all was to anything that had the polyester sort of binding around the legs because it would make him sweaty, and then stick to his skin and rub it raw
The fleece cuffs on Lovebums are so soft they just don't rub or stick at all, and I've never had a problem with them wicking into clothing.
What a shame that you had to stop using wool because of the eczema, we're the other way around - the eczema led us to try wool and we've only had a couple of very minor outbreaks since. Mind you, all our woollies are BFL!