[Boatanchors] ever so slightly off topic - freq counters?

[Eugene Hertz]

Hi all, I am looking to buy a frequency counter. And figured many on this list might know.  I am looking for something that can handle >300Mhz and there are a few I see available and was wondering if anyone know the freq ranges for these models and their opinion of them. (Several use nixie TUBES which is how I am tenuously ascribing relevance to boatanchors list!-plus this is the most helpful list I belong to!)

Systron Donner 6150A
Systron Donner 6151 
Systron Donner 6152 
Systron Donner 6152A 
Dynasciences AN/USM-245A - this might be too big for me!
Racal Dana 1992 (ok, this is solid state)

Looking for an explanation of the differences of the Systron Donner models and if they are garbage or ok and what freq ranges they can handle.

THANKS!
Eugene