psychology or teaching degree with nqtWatch
There are currently no financial incentives to complete a post graduate teacher training course in Primary stage teaching, so there would some financial sense in avoiding post-grad study.
As psychology isn't a subject taught withing the primary sector, that wouldn't be the best choice of degree to do prior to a teacher training course. Something like Eng, Maths or Science, History, Geography, Art. Music or languages would help you to make a stronger application.
Hope this helps!