I find if you use the Filters in WinUAE to upscale/downscale the screen size you can overcome the widescreen dilemma easily enough. I am using a 19" 16/10 (same as Marco) and love it!
Resolution from old Amiga chipsets will always look ordinary on newer displays. Have you ever watched an analogue TV signal on a new digital set? Same setup I guess, newer displays are designed around much higher resolution, and many Miggy games were produced in fairly low resolution in order to get better frame rates.