Short answer - Lee, Hornady, RCBS, Redding, Forster... But it is like buying anything - what is a good car, a good gun, a good lawnmower, etc.?
As with any caliber, what is your budget, expertise/experience, firearm (bolt, semi-, single-shot), discipline (hunting, benchrest, plinking, 3-gun) etc. There is no cookie-cutter answer - you want everything in one box? If you are on a tight budget, Lee. Have some money, Hornady or RCBS; then there are the match dies. But before I would buy the Hornady/RCBS match dies I would look seriously at Redding and Forster. Maybe buy previously owned dies? For my 6.5CM I purchased Redding Type-S Sizing Die with Titanium Bushing, Forster Benchrest Micrometer Seating Die, Lapua Brass, BR4 primers - no regrets. It was the right answer for ME.
Best advice from ME - it's an investment in time and money, the fun is in the hunt... If anywhere, answers to your questions are in Sniper's Hide. Do your research, find the responses that fit your shooting style, narrow your criteria, provide the audience with some background, and ask questions that you couldn't find an acceptible answer.