I've got some spare 27C4001-12's on hand, as I understood it to be a suitable replacement for the program board on NBA JAM T.E. (I'm doing an SE update, IIRC - MK2 and NBA Jam share the same platform). If someone experienced can confirm that would be suitable in this case, then I'd be happy to burn you off some. I'm fine to burn them off anyways, but at my knowledge level it would be a: "Maybe?" I'm not sure if the access time difference would matter.
As far as the 21JK-0 goes, unfortunately I haven't got any spare N82S129N's lying around. Moreover, I can't find it in my programmer ( T48 ) listing- though my programmer does have an auto function for 8-pin and below (and I often struggle to find chips in there, anyways, even when it does support it!) There's some chance it may be able to automatically adjust. The other problem there is that I don't know what's actually on that chip to burn. Happy to experiment if you like, they're not crazy expensive on eBay, but it's another maybe.