When you're use to big horse "stuff" and get these little guys, the desire to shop,shop,shop is overwhelming, I understand - been there; done that!
You might find some deals at
http://www.doublediamondtack.com/ in their close out items. I also like their halters (the $7.50)and leads as I prefer a halter that has the fastener under the throat latch so I can undo it for grooming/ clipping.
Here's another site to find fine tine forks (they're really the best for picking up those little poohs)
http://www.aplusequi...ef=MAIN6=
My personal preference for bedding is Easy Pic or a product like it. It looks, well is, sawdust but it's been "cleaned" to help reduce the dust. It absorbs well and is easier to "pick" thru so not as much waste.
The feed I like to keep simple. I feed good quality grass hay in winter and add or rather substitute part of that amount with afalfa cubes in show season. I weigh all my feed even the hay so they get 1 1/2 to 2 % of their ideal body weight in total feed (hay plus everything else). I use a supplement so I know they have all the right vitamins to go with that hay. (personal preferrence - since minis gain so easily I use Purina's Enrich 12 and they only need around a 1/2 cup a day) I also use beet pulp, wet, (but I weigh it dry). I only give about a 1/2 lb of beet pulp each morning and this is more so I have them used to eating it if I need to "hide" medicine and so they have some liquid in the diet when we travel to shows.
Be sure to go slow with any changes from what they are getting now.
You'll need, or want, the same type of brushes you had for big horses only not quiet as stiff, especially if you clip them for shows. If you shop in the mini supply places they'll be smaller and will probably be easier to fit in your hand.
You'll need the same wormers; only in smaller amounts. The same sort of first aid type items too. I keep probiotics ( akin to giving kids yogurt) around for those upset hind guts that sometimes come from worming or trailering.
I try to NOT blanket unless they are showing outward signs of cold or unless I'm sending them out and it might snow (and then temps drop) when I'm not home.
Diaper wipes are a good thing from the dollar store for use at shows. All types of clean up (horse and human).
Stall supplies much the same only smaller size. I like flat back buckets. I use 5 gallon heated ones for winter water. I feed in the smaller pails hung from those hooks that have a ring with the hook inside so the bucket stays on the wall longer (mine have figured out how to remove the buckets anyway). I prefer to ground feed. I use mats in the stalls and even outside a 3 x4 mat in each run in shed so I can throw hay there. Since there are no hooks at the shows, I take large flat pans to feed their supplement and beet pulp and soaked alfalfa.
Ok, Waaaay too much information, sorry.