50 hours of research = 1 amp for Totem Sttaf

SIMAUDIO, Plinius, AYRE ....all great with Totem so  Pick one with an edge to SIMAUDIO

because 

(1) all three are are frequently paired with Totem at the audio expos ... All are excellent.

AND ....

(2) TOTEM synergy with SIM is a fave because even Totem's own AMBER integrated amp (discontinued) was a TOTEM joint venture with SIMAUDIO based on the latter's platform and  design of amps. 

Q. Which of the SIMAUDIO integrateds  with Totem you may ask?

A. your budget drives that. Say, a used i5?

I've owned both the ARROS and FORESTS simultaneously in prior systems so I know their strengths and warts well, and the STAFFS are between them in their product line with a strong lean towards the ARROS in comparison.

i would not go hog-wild and buy a premium priced integrate amp with the price/performance output limitations of where the STAFF resides... It won't save you  and certainly won't drive you to the next level in performance.

A) In simpler words, tailor your choice of amp unit to the lower to mid price units at best as a preferred price/performance match to the STAFFs.

As a general rule, more "grunt" in the Amos is best with Totems ... WPC by themselves are meaningless and Totems crave hi-current amps. Rarely will you find them partnered at the audio expos with anything other than hi-current hi-WPC SS gear . That in itself is a noteworthy point to consider ... Ergo the SIM, Plinius, AYRE brand leanings thst they frequently use.

I have test-driven my Totems  with top-of-the line CARY tube amps  and found the listed SS integrated amps all bested it , and the differences were not subtle. 

Yes, SIMAUDIO also has its own DAC ( a fine piece). Google  the specs and reviews...better still go audition it with an all Totem/SIM setup.

I've auditioned NAIM with all of the Staffs, ARROS and Forests
ditto with SIM and many  others including inter Alia, using bi-amped ARCAM FMJ, NAD C370 etc.
i've auditioned Totems at dealers and at expos with all of AYRE, PLINIUS and SIM.

The latter three choices are a close pick one of em as a single unit integrated amp gig with a small personal fave towards the SIM.

My bi-amped (2 X 100 WPC hi-current amps ... The top ARCAM integrated and a second separate power amp ) ARCAM FMJ gear was a lot more money and IMO better performer  but that was with FORESTS whereas the ARROS did  quite nicely with just the ARCAM integrated on par any of the SS choices above.

NAIM with Totem .... Nope .... Heard 'em personally numerous times directly with ARROS, STAFFS and FORESTS with a "meh?" Grade at best.

Hence NAIM is NOT on my list for Totem speakers = not to my taste based on hands-on experience... and --IMO -- any of the above SS  integrateds will best NAIM with an improvement in performance that is not subtle.

Using the top-of-the-line CARY tube preamp and tube power amp combo as the source as hands-on experiences.... = any of the above SS amps will similarly best these tubes. As an aside, the CARY with ARROS was "okay" but not "great" in a head-to-head shootout.

With the FORESTS, the CARY tube gear was lousy at normal listening volumes (compressed, soggy, top-end rolled off, wooly bass) and required a full bore volume dial crank to about 2:30 on the volume dial to get the FORESTS to perform. The problem was that those volumes are already irritating after about 60 seconds and any loud volume is fatiguing for sure in short order in any case..

Plinius 9100 or successor model (9100SE?)
AYRE AX7 or successor model

with the Staffs the cheaper older models are more than you need with Staffs

but

any if the SIMAUDIO, AYRE, or PLINIUS allow you the better upgrade path to different speakers when you move up from the Staffs
The SIM has a very good matched DAC that facilitates further synergy 
i would start with SIM as a reference point. 

PS. Totems are speaker cable finicky . In brief, they perform best with silver coated braid .... Their own Totem Tress or say, Chord Rumour or Odyssey . The Tress are , effectively Chord knockoffs.