If it is a good source, why not give the fish a try (particularly if it is eating)? You have waited a long time and there don't seem to be a lot around. I think the medium size fish tend to acclimate better, but it is really up to the individual fish as many small and medium-sized ones don't make it. Plenty of people only want larger fish and it works out ok for them, so there is no reason to think it can't work for you.
How big are you thinking 5-6"?