HDMI AMD or INTEL

your aren't in a great situation, dual IDE HDD's, XP and upgrading the cpu later.

you aren't going to get it cheap, I found a motherboard though but you'll want a DP to HDMI adaptor. it's the ASUS M3A78-CM, you'll need a SATA HDD and maybe a SATA DVD-ROM too.

Might aswell get a 1TB since the samsung spinpoint's have lowered in price.

There's no reason to dual-boot Vista and Windows 7 when you are coming from XP.

You should dual-boot XP and Windows 7. In fact, go get Windows 7 RC right now and use it free until roughly March 2010.

Your upgrade path is hard. HDMI is pretty new, but you want the older, cheaper CPU's to put on it.

I'd get this motherboard:
Gigabyte GA-MA780G-UD3H

It supports both AM2+ and AM3. You can get a good dual core like this:
AMD Athlon X2 7750 Black Edition Dual Core Processor Socket AM2+ 2.7GHZ 3MB 65NM 95W Retail Box

You should find both for about $160 USD. This board also takes DDR2 memory which is the best deal for now. Also, the fact it takes AM3 CPU's will future proof the board somewhat. At the very least you can get a good quad-core for much cheaper when they drop in price.

I can't see a much better way to do this.

As for HDMI, it's likely if you add a graphics card this feature will no longer work as you'd likely have to disable the onboard graphics. I'm not sure what you want it to do so that's as much as I can help.

No...there are beta releases floating around all of the major torrent sites...i believe the latest release being 7100...and no having vista will not get you win 7 when it is released either..

"Thanks. I understood you had to upgrade to Vista in order to access Windows 7?"

You should either wipe out XP and do a fresh Windows 7 installation or else do a dual boot of XP and Windows 7.

Partition software is on the net, such as Acronis Disc Director. I don't recommend an "upgrade" of XP or Vista but it probably can be done.

If you dual-boot, you should start the process from WITHIN XP. I booted from the CD (which worked fine for dual-booting Vista with XP), however apparently installing Windows 7 by booting from the CD causes the XP installation to not be recognized (a real pain let me tell you).

Whatever you do, back up your e-mail, settings and data to a safe spot.