In my opinion, I would get a inspiron 9300, but if you want to choose between the 6000 and m140(also known as inspiron 630m), i'd suggest you get the 6000 with a coupon from coupon mountain. at coupon mountain, you could track deals from dell and other stuff. And why i recommend the 6000 instead is that it always has good coupons for inspiron notebooks not xps notebooks. I currently own a 9300 and i have a friend that has a 6000 and mine is much faster and advanced. Hope this helps.
I'm planning on buying either the Inspiron 6000 (Pentium) or the XPS 140 laptop from Dell. I have a lot more time than money, so I'm free to wait for the best deal. My question is, how do I know what Dell's offering and when savings are at their peak?
If anyone has anything to say about either laptop, I'd also like to hear that.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic