What to buy? Advice needed

Hi there,

I do occasional video editing / DVD authoring for events and I need some opinions on what to buy.

Should I:
A. Buy a fully kitted out 20" imac (Core Duo, 500GB HD, 2GB Ram & 256MB Graphics) from the Apple store.

B. An ex-demo Dual 2GHz G5 Powermac, 160GB HD, 1GB Ram, GF 6600 256MB with a New Dell 24" TFT monitor.

Both come in around the £1,500 mark.

I already own Final Cut express 2 and plan to upgrade to HDV later next year.

Key points I'm considering: 20" (non HD?) v 24" (HD ready) displays and Intel Duo vs. 2 x G5's.

Which is the better work-horse?

Cheers!