Best $600 integrated for Monitor Audio RX-2?

I had the Silver S8's. Similar to yours, but floor standing. Unless you have a large room or high volume requirements, the amps you list above should work OK. I list the Creek mainly for sound quality and that it was a great match with MA.

I've heard most of the amps you mention above. I would add a Creek 5350 to your list. You may be able to find a used one in your price range. I can't say for sure because I haven't listened to all the amps above, but the Creek should easily beat them for sound quality (at least for my taste's). I had mine driving a pair of Monitor Audio speakers for a while and the combo was great.

I think there's 3 versions. The 5350SE (original version), the 5350SE (classic/2nd version) and the Evolution 5350. I was talking about the first or second version. There's very little difference between the 2. Either would be OK. I had the original. The Evolution is something else. Its not made in the UK and I'm pretty sure that there are some significant design changes as well.

Here's a few reasons I like it the best out of all your other choices. For me, the biggest thing is that the pre amp section is passive. That's a really big deal for sound quality. Its extremely difficult to make a good sounding active line stage for products in this price range. But, if you find that you still need an active line stage for some reason, they make an active card for it. They also, have a couple of phono cards that sound pretty good. The amp and preamp sections of the Creek are connected in the back with rca jumpers. That allows you to use it just as an amp or just as a preamp. Since the 2 sections are jumped in the back, the signal doesn't run through the section not in use. It makes upgrades so much easier.