Looking for a new phono stage I have questions

I am interested in the GS Reflex C and likely to try one via the loan service.

I see you need to select 100 or 1000 ohm load impedance and I am unsure which is needed in my case. I will use the reflex with a Hana SL MC cartridge the specs suggest that the 1000 ohm version is correct but it is hard to marry up the specs. Hana specs say load impedance >400 ohms but I do not know if this is the same as the input impedance that GS state. Any suggestions?

My current phono stage is a Naim Stageline but it is starting to get a bit noisy and needs looking at to bring it back to spec. It sounds good through my Naim amp but I am taking this as an opportunity to see if I can do better.

I read on another topic on this forum that the 100 ohm version is OK for over 90% of MC cartridges and I did not think the Hana was that unusual.

Another question.

As I said above my curreny phono stage is a Naim Stageline and amplification is also Naim. I power the Stageline from a Naim outboard power supply (Flatcap XS) like the GS Reflex C it runs on 24v.  So I am wondering if it would be possible to power the GS REflex C from the Naim power source with an appropriate power adapter cable?  

I am OK with using the supplied power source but it could be worth a try to see what if it does anything for sound quality and it would mean one less plug to find a socket for.