I really like the NAD & PSB pairing. I've owned different combos of them in the past and it was always a very synergistic pairing. As stated earlier both are owned by the same parent company, and I'd be very surprised if they didn't use each other's gear in development. With the pairing, each piece sounds better than it would have with other gear; they really get the most out of each other IMO.
I like the T55 best out of the Image towers. It has just enough bass to my ears. My only criticism of the Image towers is that they can get a touch dry every now and again.
I'm not a fan of NAD and Totem at all. There's been something that just sounds 'off' to my ears. Totems are some of my favorite speakers, and NAD is my favorite stuff in their range, so it's pretty odd to me.
If not for PSB, Paradigm would be my preferred pairing.
I'm also a big fan of Focal's Chorus line. I've only heard the monitors, so I can't really comment on the towers, but I'd be very surprised if they didn't sound as good. NAD intergrateds and Focal Chorus monitors have always sondes great together to my ears.
You may be able to get Vandersteens in your price range. Excellent speakers. They're definitely a step up in quality over anything else I've mentioned. Haven't heard them with NAD, so take that as you will. I think they'll work well together, but I thought that about NAD & Totem too.