You won't go far wrong with Himrod which has large bunches of well flavoured seedless fruit. It needs to be cane pruned though.
I agree that Himrod is the best troublefree seedless "white" grape for the UK.
It is very early (some X labrusca genes) and gives good yields. If you don't mind a slight tartness it is edible as soon as it goes from primary colour green to pastel green, and then it goes on to get amazingly sweet - but I don't recommend leaving it to go yellow and honeyed as the berries have a habit of dropping off with 2mm of stalk attached - except the pests will have taken 90% of them by then anyway. These little bits of stalk also mean they aren't the best for drying to sultanas.
However I don't agree that cane pruning is the only way to get good yields from Himrod - certainly in the first 10 years simple horizontal cordon pruning works extremely well and is dead simple (cf. ttp://www.lindenvineyards.com/who-we-are/articles/?articleid=16).
The simplest cordon pruning is to train to an T or inverted L shape tall enough to keep the bunches off the ground - NB. it's just possible to work it at 1m high if you tie the lowest bunches back up to the cordon. You then wait for the flowers and remove every bit of green shoot more than 2 leaves past the flowers. Flowerless shoots can be removed completely or taken back to just 1 leaf.
Job Done.
In say... August - one more round of trimming back the shoots to the original cuts will keep the vine nice and tidy.
Cheers.