The last ones I got were from C/J Enterprises and being 6'5" I needed the tall also ... They had mine made and they fit like a glove ... I'm not sure if Janet is still selling vests and shooters shirts etc. but she does post on here once in awhile so you might luck out if she see's this posting ... WPT ... (YAC) ...
All I can share is that at my Orvis (Lombard IL), I just purchased one of our clearanced Ultra Suede Warm Weather mesh vests in a beautiful shade of brown ($69, down from $129). At 5'11, the vest comes down onto my mid-thigh, so while not technically made as a "long" its nice looking (IMO), the price point is definitely worth taking a peek, ordering and if it doesn't meet your needs - can be returned without questioned + Orvis quality and customer service.
www.orvis.com - click on the sale outlet link (upper right), hit hunting (left margin) and pan through the available sizes.
Gander Mountain carries vests that fit me and my son. (I'm 6'5" my kid is 6'8")I think they come in sizes up to 4X. Nice vest, decent price.
I also have an older vest that I had made by Chimere, it's a left handed vest and fits OK but the Gander Mountain is just a little longer.
Ganders vest just are made long, My son has the one I bought so I can't look at the label but I'm sure it was just an XXL. I have another buddy who's close to 6'8" that also wears a Gander vest. Your best bet is to go and try one on.