The only one that I have heard mentioned as being resistant to Marek's is Egyptian Fayoumis but I very much doubt you will find those locally either.
The ones that seem to be most susceptible are silkies and I can't remember if it is seramas or sebrights.... and cream legbars, so steer clear of those. After that it is going to be a bit of a lottery. It very much depends upon what you are looking for in a hen.... ie. egg production, egg colour, broodiness cuteness. feather colour etc. Buying as local as possible would probably be the best bet as they will be more likely exposed to the same strains of pathogens that are in your own flock's environment. Be aware that bringing in new hens is likely to expose your existing flock to new viruses and disease and if they are Marek's carriers, their immune systems could be compromised so the new girls may put them at risk as well as putting the new girl risk.
Personally I would wait until next spring/summer and see if one of your girls goes broody and give her some hatching eggs. There is much less stress on any of them if chicks are raised in the flock, than if you are introducing new adult birds and less likelihood of them bringing disease with them. You do need to be prepared to deal with the little boys that will result though or find someone who will, when they reach adolescence or pen them separately. Barnyard mix hatching eggs from a local source would be my choice for hybrid vigour. There is no immediate rush to get more birds though. In many respects, giving things time to stabilise without adding new variables is a good thing. See how this plays out and if you get a broody hen next year then think about getting some hatching eggs. Kind of put it in the lap of the gods.