Def. SMBs or Classic Equine rather than polos for all the reasons listed above from other members.
Also: check here Horse Professional Choice Boot Covers
I think the boot covers are such a great idea. I have SMB II and SMB elites
The boot covers are such an affordable way to color coordinate all your gaming colors.
My daughter goes with purple and now this year pink so I plan on getting a few of the boot covers myself.