Seriously, they're the same board (even Gigabyte admits it), except
that the DS3 has solid-state capacitors. This will prolong the lifespan of the board. However, the S3 will last longer than the lifetime of your system anyways, so if you plan on keeping your rig longer
than 5 years, get the DS3. They overclock THE SAME. Otherwise, just go for the S3 and save the extra money. Put that money, along with saving the PST into getting more/better RAM
Get 800 if possible within budget. If not, get some decent 667 RAM, don't get the Value Series crap. Get some Corsair, OCZ, G.Skill, Super Talent or the like....whatever you can afford, probably just 1 gig. Depends if you have a preference, but entirely on your budget.
Here are some options, best bang-for-buck for the good stuff here in Canada:http://www.directcanada.com/products/?sku=13220BD2886&vpn=OCZ26671024VPDC-K&manufacture=OCZhttp://www.directcanada.com/products/?sku=13220BD2084&vpn=OCZ2P8002GK&manufacture=OCZhttp://www.canadacomputers.com/index.php?do=ShowProduct&cmd=pd&pid=005766&cid=RAM.475http://www.canadacomputers.com/index.php?do=ShowProduct&cmd=pd&pid=011898&cid=RAM.475
If you order everything together from Direct Canada, you'll also likely get free shipping
But seriously, shop around. Check NCIX (usually cost more though), Canada Computers (might get lucky).
I have the 6300, S3, and 2x1024 OCZ Platinum DDR2 800..........OC'd to 3.0 ghz at less than stock vCore
. Temps are great, stable 24 hours in Prime 95 dual instances..........and runs like a cheetah