Make sure you get the exact species name of the crayfish you buy from a hatchery. If they cannot provide you with a name, don't buy them. When I say a name, preferably a scientific name. Once you have that, research it to find out if it is one of the "problem" crayfish...
If you do stock GSH, try to stock them in early spring at the largest size you can buy. IMO it's better to have less of bigger fish than more of smaller ones when stocking GSH into a stunted heavy bass population. The bigger fish have a better chance to not end up in the smaller stunted bass's mouths and when stocked in early spring have a better chance to spawn come late spring.
I also think RES would be an excellent addition to your pond with no ill side affects.
