I wouldn't buy all one grooming kit, because they're kind of cheaply made and sold for a high price. Instead, I'd pick out the brushes and put them in a tote or toolbox or something.
Here's what you need in general:
Metal curry (never use it on your horse, though, it's for cleaning brushes)
Hoof brush (the stiff kind that's on a handle - usually with a pick on the other side)
bigger tail comb
Old rags (or a sham-wow... <<<what I use... LOL!
Hoof oil brush
Braiding stuff (if you use it)
(can't live without) the rubber mit!! I use it religously - works like a charm for a quick brushing!
... and whatever else you think you need!
Every horse is an angel... They just don't need wings to soar!