you're about 20 years too late ;-)
while you may be lucky to find one that works (at least for a while), most of the old Commodore monitors are either dead or dying (i.e. will be dead very soon) and are unrepairable because the flybacks are no longer manufactured.
you would be better to look for an Indivision ECS for the A600 and use a common LCD monitor (requires A604 memory expansion as well) http://www.bigbookofamigahardware.com/bboah/product.aspx?id=1927
if you need a flyback for the monitor i recently got one from MAT electronics, a web store somewhere in the US
(a DCF1580) their numbers are dwindling though and eventually those monitors will be truly unrepairable
you can check if it's failing by the telltale high pitch squeal it emits
my ears aren't good enough to hear it so i need a spectrum analyzer app on my smartphone to detect it