I've done Kenya by the Noth Face Regular Route. We were there in October and the other side was frozen up. We had a fair bit of snow annd ice on all of the 20-some pitches. We hired porters in Chogoria which I would suggest even though it is not totaly necessary, it added to the experience and made it more fun. Not sure what the S.W. ridge route is like but the raps all needed backing up on our route so take extra webbing, biners etc. The big question for us was footware, we ended up in boots the entire climb because of snow but also did a few points of aid.
The mountain is spectacular and the climbing very much an adventure. You will have a great time!!