Canon Digital SLR Recommendation: More Storage, Nice Lens And Flash

I have a Canon 20D camera and I have used it extensibly since it came out. It is now superseded by the 40D. But I like it still, though I am shopping for some upgrades, browsing through amazon's site, I found out there is manufacturers instant rebate that brings some of the lens and flash down. I have always enjoyed reliable service from my Kingston CF cards for storage and 4Gb has never been cheaper.

I found out this is on sale:

Canon EF 50mm f1.4 USM

The 4GB compact flash card is a good fit in digital cameras:

Kingston CF/4GB-S 4 GB ElitePro CompactFlash Card

I'm still on the fence about a flash... I've been relying on quality lens, and willing to loose a shot. But this flash is onsale as well:

Canon Speedlite 580EX II Flash

Anyone else have a 20D???