For polled Herefords I think 719T would be about my first choice the Thor bull ABS has is a nice looking bull also. If you don't mind horns I agree Harland would be a good choice. I haven't seen any 3027 offspring. Accelerated Genetics has a couple good horned bulls. I know of some top breeders...
To each his or her own but I'd hate to get too far away from what sells well at the sale barn just in case the little niche market was to go south. Also, they wouldn't sell well at the sale barn because most feeders wouldn't want anything to do with them. They sure are cute though. :D
And I...
I guess those Mini Herfs are "cute" and some of them have decent phenotype, they look good in photos anyway, but I think you'd need a grass feed market to sell into. I bet on most days you would get killed at the sale barn with calves that lacked so much growth.