I would get the D80 over the D60. The D80 is a great camera. Its in the next level up from the D60 and it also has the focus motor in the body and will auto focus with both AF and AF-S lenses. The D60 will not auto focus with AF lenses.
As for the kit itself, I'm not thrilled with the 28-80 lens. 28mm is not very wide at all. I think your better off with the 18-50. The 70-300mm lens is ok. I agree with what a previous poster said about using it at the long end. Its the reason why I upgraded to the 70-300mm VR lens. That being said, I used a Quantaray 70-300mm lens for 10 years and got very good results with it. I would suggest you consider a monopod to use with it. On my June '06 trip to Disney I got a lot of camera shake images using this lens. Thus I bought the VR version not long after that trip. Until you can afford that lens (about $480) the lens you stated should be ok, especially combined with a monopod.
For $730 thats not to bad. It still gives you room to get an 18-50mm for about $100 (ebay or keh.com). For low light, if you the D80 route, then you can get the 50mm f/1.8 new for around $110. Sharp as a tack and performs well in low light. The D60 wont auto focus with that lens. Sigma makes a nice 30mm f/1.4 that will auto focus with it, but it runs around $380). Sigma is supposed to be coming out with a 50mm f/1.4 that will auto focus with the entry level Nikons, but no news right now on what the price will be and when exactly it will be available.