I am not sure what MF towels you found at NSXPO, but this might help.
Try detailers paradise. Nick is a sponsor of this site. I haven't used his MF towels yet, but his big, fluffy towel has my name written all over it. His service is top notch.
I think the 18 pack of Sam's MF towels are OK for interior and grunt work, but I use the better qualities for drying, removing wax or sealants, removing polishes, Quick Detailing, instrument panel plastic, etc.
I have used
www.pakshak.com and been very happy with their towels (email your request and the word "autopia" for a nice discount). His Waffle Weave drying towels and ultra-plush are great. I have also used his medium priced towels to remove polish/etc and they have performed and held up well.
Adam's polishes has a very nice, soft and plush micro fiber towel as well that is great for QDing. (A little soft for removing polish).
I have tried tried a few other sources for MF so PM me if you need more info.