Finally I can spend some money...

I have finally convinced my parents to let me spend some of my money on a good quality eyepiece. I got a 17mm Vixen/Orion Lanthanum a while ago, and found that I really need some more magnification. I don't want to go with a powermate, because having my eyepiece jut a foot out of my scope won't do. I was thinking either the 13mm T6 Nagler, or the 11mm. I have heard that these vingette in some scopes (I have an XT8 dob. 1200mm focal length). Also, I was told I would need some counterweights on my dob. How would I go about this, Velcro and some bean bags?
Thanks,
Zack

Another good deal is the Meade UWA 8.8. Used they are a good price and the performance and FOV is very good. Is it as good as a 9mm T-6? I think that it is very close, if not as good. Eye relief is similar in my opinion and the FOV is great.
Just one more choice is all.