Need some advice choosing...

My first and only PC that I've been using for quite some time now is a Pentium III 1Gig with 512Mb of ram and a really dodgy Fastfame mainboard. I'm not a hardcore gamer but I would like to be able to play a decent game now and then (but that's not essential). I work with Photoshop, Illustrator and CorelDraw a lot and I also use the PC for video capture and backing up my DVD's onto disc, as well as the usual mail, internet etc...

I'm finally getting round to upgrading and at the moment I've got 4 choices (Unfortunately, since I live in Zimbabwe choice is not a commodity in large supply). All are at the top end of my budget (which is not much). The main differences are:

PC1: Has an ASUS P5B-vm mainboard (Intel Q965 Chipset) with 512Mb of DDR2-800 ram and a Core 2 Duo E6300 PCU

PC2: Has an ASUS P5LD2-vm mainboard (Intel 945G Chipset) with 512Mb of DDR2-667 ram and a Core 2 Duo E6300 PCU and a 250Gig hard drive (all the others have an 80Gig hard drive) - the extra space would be nice but it's not major (80 Gigs is still double what I have now)

PC3: Same as PC2 but with 1024Mb of DDR2-667 ram, Core 2 Duo E4300 and 80Gig hard drive

PC4: Has an ASUS P5VD2-mx mainboard (VIA890 Pro Chipset) with 1024Mb of DDR2-533 ram and a Core 2 Duo E6300

Everything else is the same for each machine, and are roughly the same price. I was hoping for a bit of advice from people who know a bit more (probably a lot more) about these sorts of things than I do. I find all the different chipsets and memory speeds a little confusing. From what I've read on the internet the difference between the E6300 and the E4300 is very small. So what do you reckon? Which one would you suggest is the best option?

Thanks in advance...

Stay away from VIA chipsets, so skip #4. 1024MB is MUCH better than 512MB for Windows, so that pretty much leads to choice #3.