@juggy 

Investing on lens for now is a good idea. I will order the 50 mm 1.4g nikkor today and some wide angle lens after a little while and see the results with my d5000. Then I will think about the body. D600 is on my mind, since it is affordable with $2000 price tag and it is a full frame camera. I will also have some money left to buy good lenses. I am not thinking about switching to Canon easily, just wanting to hear from Canon users, and compare. I have very little knowledge about external flash. What should i look into when buying one?

Thanks for your input.