Down your way I'd go for Alex though you may have trouble seeing him at a show with his exams going on just now. Alternative would be Jean or David at Tristar or Andrew Bryan. Any dwarf judge should know a good Chinese. Fraser Avill in Northern has now got quite a number of Chinese including dominant spots of good type Matty. He is building up his Chinese hamstery - Cheverton Hamsters. He has an e mail address on the Northern site.
I would wait till they are about 5 weeks so they are mature enough to get an idea what they will be like