Hi Janice,
I would say that it depends. I'm not familiar with any specific MLS companies for minerals in OK but in general I will say that since the mineral rights marketplace is pretty inefficient, the more people you can get in front of will generally result in the best deal for you. A lot depends on the market perception of the specific area where you own minerals.
In any case, you will want to do some research to understand offset activity (what companies are leasing, pooling, drilling, etc. nearby) via research on this forum and on state oil and gas commission websites.
I will say that if you own more than just a few acres, it might be worth going through a site like EnergyNet to see if you can solicit bids to buy/lease your minerals. You can always set a reserve price and if that price is not reached then you are not obligated to sell (you would negotiate with the winning bidder to see if you can agree to terms).
I have purchased several lots through EnergyNet and it has been a relatively seamless experience so could recommend them. I'm familiar with but haven't purchased/sold through other sites like US Mineral Exchange or OG Clearninghouse but those are other options.
Please feel free to send me a PM if you have any specific questions about my experience and I'd be happy to help if I can.
Best Regards,
Matt Sands
Minerals Management