If the monitor is designed to be used with all screenmodes of a basic Archimedes (e.g. the A320 and similar vintage), chances are that it will work with the majority of the Amiga's modes.
Acorn used to re-brand the same Microvitec 1483 14" monitors that Commodore used to re-brand. I have both an Acorn-branded and a "native" Microvitec 1483 and both work fine with the Amiga. All you require is a 15-pin VGA to 23-pin Amiga monitor socket converter.
However, if your Acorn monitors are designed for other Acorn machines, or more recent Archimedes models, you might be better off getting some better advice!
- Ali