It's good to hear that so many other big old guys are snowboarding, I'm 44 years old, 6 feet and 260 pounds and started riding last year with my 10 year old daughter. We're having a great time riding together, she took a few lessons then she taught me. I'm riding a K2 159 wide and it's great.
This is the first weekend that we haven't been on the mountain since November and I'm itching to get back. I started riding last year in an old pair of XL Columbia pants then bought a couple of pairs of XXL Burtons over the summer. The Burtons are way more comfortable and fit great.