Ultimate Hawkeye seems super interesting. Does anyone know any Ultimate collections that give a lot of spotlight to Hawkeye?

Check out Ultimates & Ultimates 2 - these two trades are the first appearance of Hawkeye and introduce the character basically. Ultimates 2 especially is where Hawkeye gets a pretty big role.

Another trade I can recommend is Ultimate Avengers and Ultimate Avengers 2. Both books have Hawkeye as a (pretty) central character, this is basically where he goes from the regular Ultimates team to the black-ops Avengers one.

And finally there's Ultimate Comics Hawkeye, which is a solo series that details his past as well as his present operations in Tian. This one you might need a little background on the Ultimate Universe to understand, but it's still a good read.

Thank you, I'll check those out :)

No prob, glad I could help :)