I need some techy help in order a preamp--resistor values.

Usually the problem in cases like this is being scared to solder. But this is a kit. You're building it. So call em up, tell em exactly what you're doing. Not like they don't get these questions all the time. Then whatever they say, which you want to know even though it really does not change anything, because what you do is order the upgrade and try it both ways. Only way to know. Seems a waste to go to all the trouble of building and then not learn anything because you didn't swap and compare. Might as well have bought off the rack.

OK I'm not a fan of passive controls- so often I've seen them reduce bass impact and dynamic quality while otherwise seeming to be 'neutral'.
But having been in the industry for over 4 decades I can tell you that expensive resistors are expensive :)  Not only that but the lower the overall value of the control, the less effect they have.

If I were you I would see about auditioning first. If you are really stuck on a passive control, the best we have heard (and it really pains me to say this) is the Lightspeed. Its fairly cheap too as these things go.

But if it were me I'd do an active line stage before I used a passive. One problem not mentioned so much (particularly by manufacturers of passive controls) is that they are more susceptible to the variability of the sound of the interconnect cables themselves. Put another way, the lower the output impedance of whatever is driving the cable, the less you will hear the cable itself. Passives hive higher output impedances and thus often force you to audition lots of cables to find one that sounds right in your system- and even then, the only reason that cable is working is that you didn't find or hear about the one that works better than that.

JB, the Khozmo is a very nice looking piece of kit. I can't help you with advice regarding resistors, my concern is whether your amp would have enough gain to use with a passive line stage. You didn't mention that subject in the specs you listed.

I don't know how much this piece will cost you, but just yesterday I received from Modwright an SWL 9.0 Linestage, and it just put me over the top in the chase for the sound quality I've been trying to attain for all these years. As my Virtual System is listed, I really am "Done For Now".

By the way the unit I got was a trade in, which has a new upgraded power supply, tube board, and new MWI capacitors, all for $1450, shipping and tax included. The much, much better preamp you are seeking may not cost as much as you might think.

Good luck with your search for a preamp, regards,
Dan 

@jbhiller,

I would recommend you to check out Aric Audio. He can custom build anything to your exact needs. 

https://www.aricaudio.com/tube_gear.php

I have recently completed a project involving a custom 300B amp. Even though I only have about 100 hours on them, I can say without any hesitation they are the best tube or SS amps I ever owned. One would probably pay 3 times elsewhere to achieve this kind of performance and attention to detail.