Either Kodak or Ilford filters will work just fine.
The one thing you DON'T want to do is mix them. There is no consistency between the grades assigned to various filter numbers by different manufacturers. Within one manufacturer's set, the numbers denote a regular progression from least contrasty to most contrasty, and when you are printing, you choose the filter that gives you the result you are looking for. But if you try to substitute a filter from another manufacturer, you may find that it gives a quite different result than you expect.