I always look for separates. They allow you to upgrade in smaller increments and make larger investments in a specific function. All things being equal, separate generally sound a bit better as more space allows greater isolation. I would look at the idea of getting an integrated as investing $2,500 per component instead of $5,000… hence that is a big downgrade. So you’re gonna get a much better preamp for $5000. Of course you must choose carefully. $5K is a significantly better sounding price range to be in for preamps… especially if you buy used. You can probably buy a $10 K amp for $5K. That puts you in a different league. Something you might keep for the rest of your life.
The preamps that you have identified are vastly difference in sound characteristics. I’d recommend comparing them using an AI… ask to compare sonic characteristics. Then go listen to a couple… like the Conrad Johnson vs the Mark Levinson for instance, that would be a great comparison.
My taste is for detailed and musical preamps. I’d recommend looking at a used Audio Research SP28… or 27… go back as far as needed to hit your price range.
personal I find Mark Levinson to be accurate, and uninspiring, McIntosh, overly warm and lacking in detail, it’s been awhile since I’ve heard the Rogue but I’m not a fan of them. for me enjoying musical sounding preamps Conrad Johnson and Audio Research are the choices.