DC motor is fine. Don't pay for a Warp9. Waste of money. Pay scrap value (under $200, sometimes free) for a used forklift motor. They're never the reason a forklift is retired and will work for another hundred years. Call up forklift repair places or go in in person, tell them it's for a project, ask if the have any old motors sitting around just in case, or, if they have a boneyard, offer to use your own tools and time to remove a motor yourself. If they're nice they'll say yes, tell you which you can gank it from, and even tip it over on its side so it's easy to get to the bolts.