I decided to go for the 6 WM and 5 Shield. When I got to 6 PD the reticule didn't change from 5. This was still at 120 archery WPF and I didn't see the "proficiency is too low" message so I should be pretty good when I get to 135.
Thanks for that info, Corrado_Decimo. I've always been curious about that.
BlackMilk: I went that way anyway, but the whole reason for the dilemma wasn't to use a 6 difficulty shield, but for the additional coverage, HP and speed.
Iymore: I hear ya, crossbows get a lot more points to play around with since they don't have to invest in PD but I prefer bows and being at such short range doesn't really allow for safe reloads.
Thanks for the input, everyone.