I caved and bought one of John Taylor's power supplies. You cannot beat $AU12 or so, you just can't. I will persevere with the one I built for now, and see if I can quell the EMI. In any case I have enough tubes for two or three clocks (depending on whether I go for four or six digits), so it won't go to waste.
Rob gifted me with some wire, so I hope I can improve the grounding situation too. You never know, it just might come good...