the showstoper is superb for £20I think for £40 lidl is ok. one each of the 3 for £20 deal and a showstopper will give you a good half hour . Or if you don't want the duration ,perhaps an ultimate power pack instead of the 3 deal. there is a vid of it on the galactic site.
the 3 for £20 and showstopper would give a great display, there are so many good combinations, it's so hard to choose when you have only a small budgetI would agree with Cossi, 3 for £20 deal and the showstopper, i'd be happy with that for £40
It depends what you're after though?
A mixture of cakes, selection box and rockets? Or just rockets etc?
forgot latifs, maybe have a look at the guy fawkes box for £24.99 bogof, it is good for the pricejump to latifs kim when i was down your end last month they seemed to have quite a few decent offers on or try lidl for the 3 for £20 deal as it will get you a cake selection box and rockets which allows £20 to be spent on something else