34" waist. medium rearz fit like a glove. their new smaller Large also fit decently if you want the slightly bigger diaper / littler person feeling. Also the new Large is very close in size to megamax mediums.
I'm in Calgary, purchase a lot from rearz. the boxes are fine, discrete enough, although i'm sure my UPS driver wonders when delivering 10 at a time.
ABU also ships from Calgary, discrete. I will say i was daily on peekaboos for quite some time, then the next batch of M was noticeably smaller, to the point they weren't fitting well. I actually returned those, and haven't restocked from ABU since. the L peekaboo is same size as M megamax though. M Little Paws fit great, on of my other favorites.
to the original question, both are fine to order from.
Agecomfort and Healthwick are both good for megamax as well. agecomfort is usually a little bit cheaper. but megamax price jumped a lot recently. sign up for emails, wait for sales only. (same for rearz, they have frequent sales, I only ever buy on sale)