I have over 50 vines growing on my own allotment just north of London, it's a long term project but they are all growing well and starting to produce grapes after 3 years on the plot. The most pricey part of the whole thing has been the posts and wire system to support the vines, so I suggest finding a source of 7 foot posts if you are proceeding with your project. The vines I have are Seyval Blanc, Pinot Gris, Bacchus and Reichensteiner.

Good luck with your vines