From custom rom to plane unmodded OS ?

[Xpun3414]

Hi all,

Im getting a Dell Streak 7 soon & I was wondering how can I get a standard unmoded android OS that google makes The Streak has a modded 2.2 OS & I would like to root it to a standard unmoded OS. (I'll be going to HC but want to try this)
Im not sure if Im making my self clear on this. So feel free to ask me.

Thanks guys