I think the important thing is to know that there is no required brand of dry suit for DIR diving.
There is a list of qualities that a suit ought to have, including fitting well, having attached boots or TurboSoles or something similar, having pockets with Velcro, and drying quickly. True self-entry is preferred (no back zips). There are many suits on the market that meet those criteria, as Richard said.
If money is a serious object, a used dry suit can be a very good purchase. They don't sell for much of their original value, and even if you have to have the seals replaced, you can still save significant money over a new suit. The one thing you don't want to have to do is replace the zipper, because that's expensive and often can't be done locally.
Don't get hung up on brands. Brands aren't "DIR".