Which Hammer for Oly 9mm?

[M&P45]

My 9mm Olympic upper is complete. What style hammer do I need to use? Do I have to use the DPMS hammer or a dedicated 9mm hammer? I know that Colt style 9mm uppers require a special hammer but I have found nothing about the Olympic style. An email to Olympic has been fruitless... Thanks any help!

[103M 95G]

Oly system uses a regular hammer

[M&P45]

Thanks! That's great news. I have both a DPMS and RRA LPK. The RRA just plain looks like it's better made and I was hoping I could use it. I'll save the DPMS kit for a rainy day...

What about buffers? I have an H2 and a RRA 9mm buffer. I was going to use the 9mm buffer but if I don't need it I may put it up for sale.