It's worth spending the time to put together your own kit instead of buying a pre-done one. If you're dead set on buying a pre-made one, I'd recommend one of these:
And I would also suggest adding the HandsOn grooming gloves and a SleekEz.
If you're not:
Start with a good tote- Roma or Noble Outfitters would be my pick.
1. Curry comb (HandsOn gloves are the best honestly)
2. Hard brush (oster would be my rec)
3. Soft brush (I'd suggest a natural animal hair one)
4. Face brush
5. Shedding blade (SleekEz)
6. Hoof pick (noble outfitters Buds pick is the best one I've found)
7. Mane brush (Conair EquinePro or Oster)
8. Baby wipes/sponges for nostrils and dock- and face in general if your horse is anything like mine.
9. Towel for wet legs