I am 6'3", 245. I have been wearing riding gear from a British company, "
Fat Lad at the back". It fits me well, and I am not even close to the largest size they sell. I have their "Jewel bib shorts" and their "Jewel Thermal bib tights" which are ankle length for temperatures below 60F. They run between $120 - $140, depending on the USD to GBP exchange rate, and they ship DHL express so my experience has been that they arrive in 3-5 days from the time I order.