Disc isn't my MS (and quite frankly isnt my cup of tea) but keeping 2pc T9 (even for disc) I would agree being feasible.
Now for T10 you have to decide first if you want to go for the bonus. You're keeping 2pc T9 so 4pc is out of the way so we shouldnt go there;
Now 2pc T10 is an entire forum thread on its own but opinion is generally divided. Before you make your decision on whether to get 2Pc T10 be sure to read and understand
http://www.wowwiki.com/Blessed_Healing so that you understand what youre really getting. To keep it short my personal take is that its bad because its clunky, has a long gap between ticks, is based off RNG and proc stacking might actually be a bad thing :/
Now if you're agreeing (which you dont have to, just saying) that 2pcT10 isnt worth going for, then consider the shadow pieces
For the Helm, shadow Helm seems pretty good. its no spirit, and a good dose of haste/crit. Now your other options at this ilvl are Ceremonial crown or Holy T10 (no haste, replaced with alot of spirit instead), or Crackling cowl (no crit, but some spirit)
For chest, I would recommend MCR from EOF since its quite close to being the same deal from shadow t10, and will probably save you some DKP/GP/SK