Totem and Bel Canto?

The Arros aren't impossible to drive, but I wouldn't call them easy by any means. They've got an odd impedence load that requires a stable power supply. You don't need kilowatts to open them up, but you do need an amp that doesn't have difficulty delivering current into 4 ohms and less. Not sure what they actually dip down to, but I'm pretty sure it's less than 4 ohms. If impedence isn't the issue, phase angle may very well be.

A Nait 5i has a power supply that'll take care of them.

The Rainmakers and Arros are pretty similar. Totem doesn't design lines per se (as in B&W 683, 684, 685). Every speaker is it's own individual speaker. However, the Arros and Rainmakers are quite often paired up together in surround applications. Same can be said for the Sttaf and Mites. I think the Arros and Rainmakers use the same driver, but different tweeter. Sttaf and Mite is most likely the same thing.

Just a heads up on Totem in general.

I have owned the NAD T747 and although my current Bel Canto DAC and Amp combination was per-dated by some other components I can offer two opinions. First, the Bel Canto should blow away your current NAD as it did with mine with both Focal and Dynaudio Speakers. Second, I would highly recommend the newer Bel Canto C5i overe the older, less featured S300iuas I believe it to have a better amp section and a substantially better DAC.

I have bel Canto 2.7 DAC / peramp and a REF500S power amplifier hooked up to a pair of Totem Sky Towers and the imaging is beautiful along with a great sound stage. Compared to another set of speakers I have that don't produce the same amount of bass even though they are bigger Focal 826.. The Focal  are more sensitive but drop to 2.6ohms and are diffucult to drive in the bass regions ' they roll off considerably and need a sub. Whereas the Totem only drop to around 5 ohms and don't really need a sub in a small to medium room. The Totem has aa bigger and fatter presentation than the Focal that just sounds right. The Focal in fairness are a lot cheaper and do impart a house sound that has lots of space around the upper mids and Treble. The Totem are more addictive though in my view.

Replaced the REF 500s with my Exposure amp much more suited power-wise to the totems. The REF500S could lose subtlety and just be very Brash with some music. The match was not perfect. Would definitely recommend Exposure with Totem thinking again about it. Particularly the xxv rc Integrated. plenty of power and not overkill like the ref500s... I do however love the Bel Canto 2.7 DAC hooked up to anything.. In fixed mode it just gets out of the way. Now listening to properly paired gear I can hear the quality difference between the cheaper focals and the Totems. The Totems win by miles.