Thanks tt82, I considered that smaller type like you linked, but they typically copy at 6MB/s, whereas the larger faster ones copy at around 120-200MB/s. The smaller ones would therefore take 3 hours to fill up 64GB. The larger type will only take 10 minutes - quite a big difference.
These are the ones I'm considering:
SanDisk Cruiser Extreme 7.1cm long.
Corsair Voyager GT unknown length.
Kingston DTHX 7.5cm length.
So worst case, is there at least 8cm available in the V40?