Damaged trans?

Not what I wanted to read but it my save the tranny in the end. Where can I get the sprag kit? Does places like summit or mancini offer them? Anything I can do to add strength while im in the while being on a budget? I was getting a vibration off the launch now that I thought about it after I read those postings too. Im hoping I can rebuild it myself I am not to fimiliar with trannys I've done one in my life and I believe it was a 4L60E out of a chev truck. Might as well do a complete rebuild with clutches and bands too. Thatnks for the reading materials guys.