The problem of using a 112B is that if anything goes wrong with it, it will cost much more to repair than the price of a cheap modern ESC and 112Bs weren't the most reliable of ESCs at the time.
Modern brushed ESCs are readily available and there are still many more brushed ESCs around than the latest brushless systems. Just because most people use brushless systems for racing doesn't mean there aren't brushed ESCs for the much bigger group of non racers. Any modern ESC will work with your old radio.
For suggestions of what will work have a look at the
Modelsport Sniper RV12,
Nosram International,
LRP Super Sport. Alternatively there should be plenty of spare high end race brushed ESCs available second hand for not much money, I probably have a few knocking around myself if you are happy with a forwards only ESC.