All the $prem datas are produced by the data providers, not the exchanges. There are only two that do it well to my knowledge, and those are tradestation, and esignal.
With esignal the symbol for the minis is eprem a0. That's a zero.
You may be able to get this with their new emini live data deal for 45 bucks a month, not sure, otherwise you'll just need the basic live esignal package. I believe live charts also has it, and that's only around 20 bucks or so a month. That's the e signal live charts.