I'm a student pilot, and I've built about 20 hours on a Cessna 172. I also have an old ankle injury that makes it hard to bend my left ankle, and I'll probably be getting an ankle fusion later this year. I know I won't be able to work the left brake with a fused ankle. Are there any good options for trainer aircraft with other kinds of brakes?
There are still many Ercoupes in the fleet that don't even have rudder pedals, never mind toe-brakes on the rudder pedals.
You may also want to consider arranging for a more commonly-available trainer (e.g. Cessna 152, Piper Tomahawk, Diamond DA20, etc.) to be equipped with hand-controls for braking. This is done for individuals who have any number of reasons that they can't operate the rudder pedals with their feet, such as paraplegia, deformity, etc.
See e.g. https://www.freedomintheair.org/hand-controls/, https://www.newmobility.com/2019/01/pilots-planes-hand-controls/, https://www.wired.com/2009/08/hand-control-airplanes/, https://abilitymagazine.com/hand-controls-for-flying/, etc.
Russian/Soviet GA trainers Yak-18T and Yak-52 have a manual brake handle on the yoke/stick. The latter is quite common in the US, but being an aerobatic airplane, it may not be very suitable for your experience.
The Australian Jabiru light GA aircraft have a brake handle on the central post between the pilots.
The 1964 Piper Cherokee that I rent has inoperative toe brakes. In order to stop the aircraft after landing, you have to slow down past the maximum taxiing speed using aerodynamic braking. Then, you use the parking handbrake to come to a complete stop.
I have never had to make an actual soft or short field landing with this aircraft. But, it would be challenging. Personally, I would avoid it. It might be even harder in a Cessna 172. I have not flown one with a handbrake as responsive as that Cherokee.