I've received good service from all the following over recent years:-
Newsbox Fireworks
Epic
Shellscape
Jordans
Pure Party / Spyrotechnics
A40 Fireworks
Firework Crazy
The Firework Store
1st Galaxy
Used to buy bits from the factory shop and seasonal stores. But this year I'm using epic and fireworkcrazy, and spending far more than I ever have, only good thing is at least I know all of the products will be of good quality
This year, probably just seem any bits and bobs around locally that catch my eye. In the past I've driven all over the place to buy fireworks- Epic are always good, Great Northern Fireworks of Leeds is a well run shop, with some good lines- and some interesting new stuff this year.
Over the years i have had great service from Epic,Newsbox,firework Crazy, Universal Fireworks in Kent,Bracknell Fireworks(now Star). It depends where you live but Jimmys(Epic) has a brilliant range this year.