I would be in the market for a few of the 60-66 high hump mats as well. I have purchased several mats from classicparts.com and have been happy with all of them. I would say the poorest quality one I have bought was the 60-63 high hump back when they still had some in stock.
I have been considering buying a 67-72 high hump mat to see if I can make it fit. I did something similar for my '60 C60. Since the big truck mats aren't reproduced and they have a very low center hump, I bought one for a 67-72 with an automatic and did my best to make it fit. Its not perfect, but certainly better than the alternative. And if you're just wanting to make it a nice driver, it would pass most critics I think. Link to that thread is posted below.
http://67-72chevytrucks.com/vboard/s...ight=floor+mat