where did you get it and how much did it cost, and what did you get and do you recommend the place?

Im going to be getting a 700r4 for my 77 K25 as soon as possible. I have a th350 in there now and want to replace the leaking terd with an over drive unit. I know there are more than a couple websites that sell 700's w/o a core.. what are y'alls experiences?
mike