I might think about Douglas from Walmart. They seem to get decent reviews, and are available in lots of places, in case of roadside issues.
Personally I'd go up a tier on tires, often a few bucks more means they are cheaper over the long haul. As in, a $300 set that lasts 20k is more expensive to run than a $400 set that lasts 30k let alone 40k. I'm partial to RT43's although Cooper CS5's get good marks around here too, and might work well for you, being more south (RT43's hold the edge in snow). I'd at least look at the cost difference before just ruling out a better tire.
But I understand that minivans often chew up tires. And a new set of tires will beat a worn out set, any day of the week. [There is an article some place where new Chinese tires had better braking performance than Michelin's that had 4/32's. Of course, worn out Chinese tires are not going to be very good!]