Nick, thanks for the links to Jason's stuff. As far as I can see he didn't stat anyone, but I'll definitely borrow his character sheet.
Thanks for all your input guys, Having not used the mechanics yet, I value your insight. As an update:
I am planning to allow PC's to start with attributes up to 18 and skills up to 75%, as usual. I'm also planning to add a skills cap at 120%. This should allow the characters room for progression, and make sense of the upper-echelon characters in GRRM's world without allowing things to get out of hand. And for the record, I've decided that those upper-echelon guys (like Barriston, Jaime, Arthur Dayne, Garlan Tyrrel, et al) will all be statted with their prime skills in the 90s.
I'll probly end up writing up house rules and character stats for some of the big names, and if I do, I'll put them up here so that other people looking for ideas with an ASOIF campaign can find them.
Thanks again guys.