For lenses, if your looking at the 50mm f/1.8 then forget about the D40. You wont be able to use auto focus. I have the 18-70mm andn it is a fine lens, but I believe for about the same maybe a bit more you'd be better off with the 18-135mm. Especially after seeing Ed's sample pics, its a great lens and the added reach over the 18-70 is pretty big.
For the 70-300mm, if you can afford it (this is where money comes into play, get the lesser expensive body and you can get more/better lenses, IMO 6.1MP is more than enough, I've printed 11x14 from my D50 croped to 75% of original and the clarity/sharpness is outstanding) anyway, the VR version of the 70-300 is EXCELLENT. I find it to be sharper than my 18-70, it also has a better auto focus than the 70-300D or G version. I really like having the VR to help avoid camera shake especially at the 300mm end. I've also gotten usable images with VR on at a 1/6th shutter speed.
You can also pickup other used primes for very good money on ebay or at keh.com. I got my 90mm f/2.8 macro at keh and the lens is outstanding. Got it for about $100 off the new price and it is in perfect shape and is so sharp that it will cut your eye.