Jake,
Opinions are all we can offer...ultimately you must choose the course of action best for you.
Please don't take the following as a negative, it is certainly not meant that way...but if you do not know how to recognize a grass carp, then, before taking on the task of restarting an 8 acre pond, you may want to enlist the assistance of a professional pond manager (not someone who is selling fish) to evaluate your specific situation and make some recommendations or present you with options. We can all guess at possible approaches from a distance, but a good on-site knowledgable expert would be very helpful to you.
The very best that I know of is the one who is the "Pond Boss". Contact Bob Lusk and try to get him to do an evaluation for you. He is a very busy man, but good people always are.
