Dilemma, which lens to buy with a 60D?

Hi everyone, I never posted here so I'm a bit scared d:
Btw,

I'm a occasional shooter, but I don't like having problems with my camera. I'm planning to buy a canon eos 60D, changing from olympus e-520, basically cos olympus is not producing anything I like lately, and I'm interested to have the option of movies too... with the olympus I had the 14-45mm and the 40-150..

but I'm not so happy with those, cos none of them has a nice reduced depth of field at 50mm and cos the AF is so slow and disappointing...and at high iso is working really bad...

I've been using it for 2 years and I'm planning to buy something better, but being a student the money is a problem...I think I could afford around 1500€, but with those I couldn't buy what I want...
for sure I want the Canon EF50mm F1.4
but I would like to have a good zoom for the walkarounds...

I've been reading some articles and I was thinking to buy the 15-85mm but the price is really high, and I would like to know your opinion about it... it's not in a kit with the 60D, and this affects the price, is it so much better than the 17-85 (which is in a kit), or you think that I should go for a 18-135mm? is it a good lense? I'm scared buying the basic kit lenses, cos I fear I'll be disappointed as with the olympus...
thank you a lot, and sorry for the long message (:
Daniele