Wage cap has problems.
If the FA bring it in, then the best players will go to Spain or elsewhere.
If UEFA bring it in, then the best players will go to tax-free clubs like Monaco, or corrupt nations like Russia who will give under the table money.
The best thing to do in most situations is not to regulate it with rules and so on, but to let it self-regulate. The poorly run clubs who pay too much will go bankrupt, good. The well run clubs with sensible owners will flourish. The problem solves itself.
They can't ALL go to Monaco.. :-)