I'd recommend a SCART adapter for the Amiga video output.
One thing you might want is a way to burn Amiga ADFs to Amiga floppies.
To do this, you could get the Hombre disk -
http://eab.abime.net/showthread.php?t=27704You can burn compressed ADFs to a Double Density (720KB) PC floppy, then read them on the Amiga and write to a disk (again, Double Density). The Amiga fits 880KB on a 3.5" floppy disk.
Does the A500 have 1MB RAM?