Since you're working with medium format film and will ostensibly be enlarging your negatives, I would avoid pyrogallol based developers, such as Michael and Paula use. Their negatives are too dense to be printed on enlarging paper.
I think your best all around choice would be Pyrocat HD, which has already been suggested. It can be tailored for negatives to be enlarged and has the extra advantage of also being good for contact printed large format negatives with a little fine tuning. If you ever decide to contact print bigger negatives you'll have your developer.