[X-Newbies] cctv hookup to display

[Cy]

Not sure if this is the appropriate forum for this question, but here 
goes...

Because of vision issues, I need to use a Merlin type closed circuit tv 
reader to read checks, legal documents, etc.  Since I am now lusting 
after the MacIntel to  retire my 450 G3 iMac, I thought to use the same 
display for the Merlin reader and the Mac.  I can't see this working 
with the all-in-one iMac, unless it has a separate video-in. That would 
be all I need, right? Right?  Separate display and the Mini?  Other 
solutions? Or am I reaching too far here?

Any remarks or comments are appreciated.

cy