We've have Tullameen and Malling Jewel. What you need is a few different varieties that crop earlier or later in the season along with an autumn fruiting raspberry like Autumn Bliss. Other good varieties are Malling Leo, Glen Ample and Glen Moy which starts fruiting in late June. Living in Buckingham you will be able to grow any raspberry variety you wish.

Buy them as bare rooted canes in autumn from a specialist grower.