What brand tubes do you recommend without breaking the bank?Since there are so many choices for the 12AX7's and 12AT7's used in this preamp, it might be helpful to say how you would like to change the sound you have currently.
Also, I suggest changing the line stage tubes first, unless you are completely happy with the sound of the CD player, as these change sound on all inputs. Then change the tubes in the phono stage.
Here is a tube layout diagram. V1, V2, V3 are in the phono stage, and V4, V5 are in the line stage.