Hi, nice to see a fellow Hungarian around here (want to take a Hungarian Model M off my hands?)
Anyway, you haven't said if you want blank keycaps, UK English, US English or Hungarian legends. Hungarian is impossible or nearly so, blanks are easier. If you have an ISO board and get ANSI keycaps, you might be a keycap or two short (ISO has an extra key by the left shift and a different layout around the enter key, and keycap profiles differ from row to row so they're not interchangeable).
So first decide if you need ANSI (US or blank) or ISO (UK, Hungarian or blank).
Note that even apart from the physical differences, US and UK layouts differ wrt to special characters as well, e.g. see some of the number keys:

