This should work, yes, using one pair per channel should give the best results because tubes of the same manufacturer are more likely to have similar specs.
The correct bias settings should be indicated in the schematic.
Rodeodave gave the best answer. Watch those Gold Lion KT88's though. I have not used them myself but I have read many reports of premature failure but of course that could be caused by miss-use. You should bias the valves for 0.55V on the test points provided. The bias adjust controls work in reverse to what is expected, i.e. turning the control anti-clockwise INCREASES the current through the valve rather than decrease.
ok i have the new valves now. i am going bias them today on the amp witch is positive and negative red or black. and also what setting should i put my mulit reader on kind regards mr young