You can get good ankle braces from any local sporting good store, and even some pharmacies. You want to get simple slip-on ankle braces. Cloth/elastic braces will work fine and will usually run you around $10 a piece on average (like this one here
or this one here
). Some brands are cloth/neoprene braces that are a bit stiffer and more expensive which would do fine too. My gripe with those is that they don't breathe as well and you wnd up with wet, stinky braces after wearing them in practice.
The stiffest type are the lace up kind, but you wouldn't want to use that for Martial Arts training (like this one here
). The laces sit on the front of the brace with the eye holes facing forward. You can probably surmise it's a recipe for scrapping up and cutting your training partner up if you wear them during sparring. Also, avoid the wrap-around type that closes with velcro (like this one here
). That velcro will scrape/cut just like laces and with too much activity the brace will undo itself and come off.
It doesn't matter if you agree or disagree
... As long as I don't bore you and I spark a moment of thought, my goal is achieved
Queng leon queng tigre ecu tacacut, queca pa? - Pampangan Mandarigma Motto