I respect Gaius' opinion most of the time, he likes a well put together and streamlined system and has (for whatever it's worth), good taste.
But to write off the possibility that something might be a good match (might) because it's not of the same brand I think is perhaps a bit foolish. (Bear in mind, from a retailer's perspective it's often easier to just keep sh*t simple....and often for good reason).
The longer NAIM builds products the more their stuff tends to work more openly with other people's products. An example is the Statement (obvi) but also simply by adding RCA jacks to pre's and/and. A set of IBL's really sounded like garbage onanything other than a 32/hi/160 IMO or better....you couldn't hook it up with a nakamichi receiver, for example. I mean, you could, but it would've sounded crap. Same with even a linn pretek/powertek or even kairn/klout for that matter. Not knocking a Kairn/Klout but they just wouldn't really work with even SBL's.
If you found that you like NBL's Aand Ovators I think I understand. Having had some experience with both. (although let's be frank, we all somewhere deep down inside, if we admit it, all want just one extra room somewhere to put in a fully loaded stack of DBL's. Go on. Admit it.)
The Ovators are tremendously capable and also tough to drive. Of course you need a good source and pre-amp.....but powering them with a chord SPM might be a very good idea actually. Chord's have tremendous grip and control and a fairly well balanced sound, not too bass heavy.....and I agree with the 300/500 comment above but that's not to rule out that a Hi-Powered chord might achieve similar results.
As for the 272 I haven't heard it but let's be frank, it's newer than a uniti and a standalone pre-amp with latest ideas and innovations brought-in....I'd be shocked if it wasn't a really solid pre-amp/streamer/dac and didn't do very well in comparison to a S.Uniti as a pre-amp....being similar but a level up.
I'd love to hear how the ovators reacted off a chord but alas no time or availability to make it happen. But if you do get the chance to experiment...do it. Cabling will make a huge difference to your results, both from pre-to-power and speaker level, so be sure to allow to play around with that stuff in your trials.