Talk Business, a multi-format Arkansas newsmagazine, is conducting a whole bunch of polling on the state's congressional primaries. They are using an outfit I'm not familiar with, with the memorable name of "The Political Firm." They look to be a Republican pollster, but I don't know if they have any skin in the game (or if Talk Business has any axe to grind).
In any event, Talk Business says all the polls were taken April 6-7th, were of registered voters (sort of an unusual choice, given that the primary is on May 18th), and are unweighted. TPF says it uses IVR (aka robopolls). Talk Business also promises two more rounds of polling before the primary.