US made, integrated tube preamp able to handle KT150 tubes?

Most amplifiers that use the KT150 tube, are also backwards compatible with KT88 and EL34's so there are many tube rolling options available :-)

Right now all I have to go on are reviews that I have read. I am open to other tube options.

McIntosh isn’t bad 

I know you stated KT 150s, but IF you might consider KT 120s, then check out Rogue Audio's Cronus Magnum III which has had several significant upgrades from the Mag II. Made right here in Northeast Pennsylvania for just under $3000.00

I second the Rogue, understand you’re looking for an integrated but consider the RP-1 Pre and the Atlas Magnum II power amp, yes it runs KT120’s not 150’s and yes, it sounds superb. They are right in your budget new, available pre owned for less and made in the Good Ole USA....PA.