Thanks. I'm old; my eyesight ain't what it used to be!
It's exciting when there's a new horse on the horizon, so I can see why you're beside yourself.
As far as buying things on-line, I'd recommend Jeffers Equine, Valley Vet Supply, Chick's, and Schnieder's Saddlery. Stateline, SmartPak, and Dover can be kind of expensive unless they're having a sale, although I highly recommend SmartPak if you can get a good deal.
I have a TB, and tend to buy him full horse sized halters and bridles. The only issue I've had is that one bridle's noseband was too low, but I used my leather punch and put more holes in it, and now it fits fine.