In hunters any boots or bandages are prohibited. For Equitation the USEF rule book states "boots and conservative colored bandages are permitted". I'd be careful at shows though, esp if you do both. I've seen people forget to take them off for their hunter rounds and get disqualified.
As far as brands go, I think Eskadrons are great, but I'm sure there are cheaper brands out there. I would highly suggest getting Eskadrons (or similar) with the "Flexi-Soft" option. The 'regular' kind has been known to dig into their tendons and cause lameness.