hi watt pre-amp [emulator help needed]

[donald stringer]

http://www.firebottle.com/ampage/schems/hwpre.gif I wanted to try my hand at this. Am I correct in assuming that the pre-amp in the link I have posted is showing two inputs? May I eliminate the bottom input and secondly I am taking the output off of the 250k pot. Thirdly in order to get this off the ground I am just taking the values off of the schematic or would I have to devalue in some way. I guess that I would put 100k trimmers on the drains of the jfets to bias them yes, no, maybe? I think the second input is padded down[ yes, no, maybe]