check out www.r1150r.org
go to the message boards and there's a rockster forum there. i just got my rockster a month ago and i like the naked look but the blast was a bit too much for me. wunderlich makes 2 different screens for the rockster. the "low" and the "trimm".
i got the "trimm". it's the smallest one they make. i'm loving it so far. it takes the blast off me and it's quite adjustable and i'm still fine tuning the adjustment for me. i'm 5' 8" and i've got it adjusted where the wind is blowing just at my forehead (i think). but i know that my highway riding is much easier to deal with.
i got mine from santa cruz bmw and you can order by the part # 8110350.
you should check out that forum though and there's a thread about different windshields.