Hi David,
WonkyDonky (Dave Price) is your man.
He is a member on here but I can't remember seeing him on here for a while. Very knowledgeable chap and his kits are very good; I have one in my .22 99S. Dave uses springs made to his specification and the kit will come with bespoke, matching guide and top hat. Highly recommended.
Other options - The Tinbum kits are very good and available in various stages. So you can buy just the guide, top hat and power adjustment washers (+ Bumslide) or a kit which will include these components mated to a spring, so you know 100% that they will match the spring exactly. Or you could whip the spring out, post it to him and he'll return it with the matching items. Make sure that the spring ends are flat and polished and, once allied to these components, refinement and shooting manners will be very much improved.
V-Mach. Superb kits, but I hear he has been ill of late and currently working reduced hours, so not sure on availability. Again, kits or spring / guide sets available in different configurations.
There are also SFS (Sandwell Field Sports) and Welsh Willy kits to be had. No first hand experience of these but I doubt they would be anything other than excellent.
Hope this helps.