You just opened up a can of worms with that question. No 2 answers will be the same. But I'll go first. I know people who use the stock D5 with little or no probs. I have a D5 that has been modified to 2800-3000 stall. I have no spool up or lag. But there are many good choices out there, it just depends on the money you want to spend. I think mine was $175 with a core, and they told me anytime i had a prob just bring it back. I had it rebuilt for the heck of it when i got my new tranny and they replaced everything for $75. Hope this helps.
Scott