Hi Marko,
i can recommend a HP 3569A - portable hand-held Real-time Dynamic Signal Analyzer.
I know, it is very old instrument, but one stand-alone, incredible sensitive, accurate and reliable analyzer.
Technical characteristics are classes better than proclamated.
Among other things, for me is the most fascinating the ability to measure levels down to almost nV range, very useful for
evaluating a noise floor in audio equipment - you can get precision and consistent results on HP 3400A level, if not better.
One almost forgotten gem!
Regards