There is No Such Thing as a Frozen ATPL.
People incorrectly use the term Frozen ATPL to indicate a CPL with Instrument Rating and passes in ATPL Theory.
You can not be issued a ATPL until you have 1500 hours flight experience.
What country will you be flying in? That usually determines the licence you should try and achieve. JAA for Europe, FAA for USA,CASA for Australia, Canadian etc. Can't usually fly without a licence issued by the Country of aircraft registration.