Doepfer

I have been looking at Modular setups for a long time, especially Gear 
by Doepfer and Analogue Solutions.  I presntly have an ARP Solus and a 
Moogerfooger setup that I want to use a sequencer with.  I am looking 
at the A154 and A155 modules.  If I am only looking to vary pitch, 
would there be any advantage of the A155 over the A154?  I am only 
looking for a very simple sequencer.  Also, I know that equipment from 
AS can be powered from Doepfer case, can Doepfer equipment also be 
powered from a AS case?

Thank you for your time,

Ron....................