Hello,
have you ever tried a saddle without a cutout? If you're getting **blisters** (ouch!!!), it sounds like something is causing excess friction. Personally I can't ride saddles with cutouts (I get something more like bruising than blisters, but bad enough), and I can be quite comfortable with a non-cutout saddle (currently riding a Fizik Arione with no saddle discomfort).
Just a thought...