PPs have addressed the issue of which credit card is best for a DVC Direct Purchase, assuming by "best" you mean that you want to take a long time to pay it off.
Have you thought about the credit limit?
I don't know if this is your first time purchasing DVC, or if you are adding on. If this is your first time purchasing DVC, and you are purchasing a WDW Home Resort, the smallest this purchase could be is $21,500 + closing costs, for AKV, SSR, or OKW. That's $215 per point with 100 point minimum purchase. If you want to be eligible for Membership Magic perks, you need to buy at least 150 points direct.
I assume you know that
https://dvcnews.com/dvc-program-menu/financial/pricing-a-promotions has pricing for DVC direct purchases. If you want to look at DVC resale options for a price comparison,
https://www.dvcforless.com/ is a cool website which aggregates the listings from multiple agencies.
Caution: that last one is addictive! When I heard about it recently, I went to the website to check it out, saw the perfect contract, and ended up adding on when I had no intention of doing so.
And if you are already know all of this... Never mind (which apparently was said by Emily Litella not Roseanna Roseannadanna, which was news to me until I googled it to get the spelling).