Depends how swiftly you need it. If you are heading to Kelso you'll find any number of traders with top quality gear on sale - and there's nothing to beat being able to compare items to see what you prefer and what deals are to be done.
Blatant advertising - we'll have cleaning gear there. I'm sure Brock & Norris, Ivythorn and a number of others will too.
At the top end, there is very little to really differentiate well made and designed gear - it really comes down to personal preference. Anyone wishing to argue the merits of Tipton, ProShot, Dewey et al rods frankly needs a girl friend
Spear tip jags get my vote - maker issues as just mentioned. Brushes are contentious, if I do use one its a quality nylon type - usually Dewey.
A good bore guide that fits well, seals the chamber from solvent leeks and doesnt fall out - look for those design features and you will naturally come across the good models.
Something to keep jags and brushes in - MTM Jag box
Something to keep your rod clean - 38mm or bigger plastic pipe and push fit end caps from B & Q
Can of brake cleaner - to clean off jags & brushes and to shift carbon fouling
Solvent - take your pick. I like Butches Bore shine, but not prepared to enter a duel to the death with someone who has a different preference
Bore Foam - I like it and find it works well - others have different views. Forrest Bore Foam has worked well for me for years. There may be better out there, but never felt the need to change.
Good grease and lubricant/ Metal protector.
Cotton Buds.
Good Patches.