Which external HD case

Hi all

I've just pulled a massive 20GB hard drive from my old seriously
non-working G3 iMac (Summer 2001) prior to dumping it. The iMac failed
some years ago and I didn't have a backup so now have the chance to
check what's on the HD. Any recommendations for a cheap and cheerful
external HD case and supplier? There's loads on ebay for about £10. I'm
guessing they would do. I've never connected up anything like this
before, so are the boxes and internal plugs all standardised fittings?

TIA for any advice.

Ivor