Of course you will need a Tanker endorsement. If you are getting your HazMat, go ahead and get a TWIC card. It’s the same fingerprints and background check. Some companies require TWIC. Some facilities require a TWIC card. I think the cost for TWIC is $125.
As far as I’m concerned EVERY driver should get Tanker, HazMat, Doubles/Triples endorsement. Other than HazMat they are just a few questions on the computer. HazMat is expensive, maybe about $200. TWIC is $125. TWIC is used at SOME facilities for additional ID. Having HazMat, TWIC, plus endorsements above allow you to work almost anywhere pulling almost anything. If you can afford it, have a clean background, I would get them. Your Mileage May Vary.