Best Tube Preamp & SS Amp Combos

I am looking for opinions on tube preamps and SS amp combinations. I currently own the Pass X-1 and X-250 SS units. I would be looking to spend $5K - $10K on the combo new or used. I recently heard the Sim Audio W-5 SS amp with the Art Audio new Gill tube preamp and it sounded really nice. I will probably try the Art with my Pass but would like to know what other combinations to consider.

Thanks and Happy Listening.