Trek 8500 frame

Hi, I have recently bought a Trek 8500 frame with the dream of assembling a bike. But, I made a little mistake. I had a budget of 600£, and I used about 400£ of them on the frame - yeah, stupid I know.

Now I need some assistance. Wheels, seat, handlebar isnt the big problem, my problems start when I shall choose between Shimano dura ace, Alivio, etc. I do not know what to choose, so I am a little lost. I also need to choose a fork and some brakes, but is that the right place to save some £? I am a little lost.

The bike should be used to city transportation, but a lot of it. The essentiel thing for me is to get some cheap gear with high durability - I can always upgrade, that is also why I bought the 8500 frame, it will last a very long time :-) I am willing to go a little beyond my budget, but I reckon that it should not be necesarry.


Sorry for grammar errors, sometimes my english just fail.