I think it's a good idea for you add the Valks as your open distance driver, but I would not stop throwing those slower discs, especially the Gazelles. Gazelles have a lot more range than most would think, and they are wonderful discs.
If you just have to have something with more D, I would go for a DX Teebird. Wraiths are good discs, but you'll be better off holding off throwing them even if you are tossing them 350'. I used to throw Wraiths, but I switched down to Teebirds as my primary driver and throw SOLFs for open D. By learning to throw Teebirds, I can get them out as far as I used to throw Wraiths with much more accuracy.
When life gives you lemons, stick them in the freezer for a few hours, then throw them back, 'cause they're like rocks, man.