I go to Spire Hospital in Bristol (used to be Bupa) they do dating scans 99 and OSCAR 189. If you want like a 3d with a dvd I think companies like Babybond do such a thing, they are about 200-300 I think.
I live in the south west and my NHS hosptial no longer tell you the sex either. There are lots of companies who do this but am sure Spire would for the price of a further scan. I found out with dd only as I am very anal and I like to know exactly what is going on. Was not at all bothered which sex just so that I could know!!