I am looking to getting a slim also, towards the end of august tho. I was looking at some bundles to save some cash and make the dollar go the extra mile. Here were my two options:
Walmart: Players' Choice Bundle $399.99
120GB PS3 Slim
1 Additional Dualshock 3
2 New/Used Games
Should come out to $399.99 + tax + shipping.
Costco: PS3 online $299.99 - great for their lifetime return policy
120GB PS3 Slim $299 @ costco
1 DualShock 3 Controller @ Amazon (free prime)
3 Used Games at GoHastings B2G1 $1 Sale
Should be a little bit more than the Walmart bundle but you get 1 extra game depending on your choices for me: RDR, GOW3, Batman:AA
If your set in just buying the console, I would suggest going to Amazon as they charge no tax and I pretty sure you can get free super saver shipping or something like that and pocket the rest of that money to pickup another dualshock 3 from Amazon. You can also check out Craigslist for some good deals. And 120GB should be good for you, I have a spare 500GB harddrive that I plan on putting on the slim, so you can upgrade later