as someone said you can cover the HD hole with tape...
An A500 won't allow you to easily transfer adfs from uae etc... I would go for a second hand 1200... you'll get a computer that will run almost everything the A500 ran, you'll be able to access pc formatted disks more easily thanks to the OS, you can plug an ethernet pcmcia, cheap accelerators, you can plug it directly to your TV... The A1200 is a great little computer :-D
-edited- If you decide to buy an A1200 and you want to plug in an ethernet pcmcia you'll have to use a 16bit ethernet 10 card (ethernet 100 won't work...)