If I don't remember horribly badly, you can easily use a 10pin for a 6pin standard connector. Any Odd-pins-per-row and any even-pins-per-row match each other as long as the plug physically match.
Either way, why not ask them to send 10p and 12p samples to try? Ass the Females while you're at it. Worst case you have some stock for your next weird plan.