In all my recent testing I had no issues with Picasso II and generic Dell 19" monitors. They're decommissioned from our office PC's so perfect for an Amiga, especially since they're not widescreen. Make sure you remove the resistor on your PII board. Models like 1906fp, 1907fp, 1908fp... Dell has about a million different model numbers, all basically describing the same thing. If you can find one labeled "ultrasharp" those are usually brighter and crisper.
This one should do you just fine:
http://www.amazon.com/1908FP-UltraSharp-19-inch-1280X1024-Adjustable/dp/B002JNR3R4/
