Need help ! Looking for a low cost integrated tube amp for my office

Yes, a used NAD 356BEE could be found for under $400. Has 2 sets of speaker outputs and an extra set of pre outs. One could set up 4 channels for the 4 Haydns.

If your NAD has “pre in” jacks, I’d get a Schiit Freya+ preamp and get my tube experience that way and upgrade amp later if you want.  Or a used Freya and Vidar would be a nice pairing for not much $.  For an integrated you’re probably best off with a hybrid like a used Rogue Sphinx, Peachtree, etc.  Best of luck. 

Thank you everyone Great info !