Vic Smith wrote:

Have you considered a composting head?
Seems it would save space and cut out all the plumbing
and leaking crap. Not cheap.

Here's somebody who uses one and give a good account of his/her
experience with it.
http://www.sailsarana.com/FAQ.htm#why

--Vic

Yes, I considered a composting head. The ones
that I'm aware of have significant issues yet to
be overcome in terms of the space and power that
they use.

Don W.