Mira Groupware platform - architecture suggestions

Hi,

I am the Team Leader of an Open Source desktop-based groupware
platform dubbed Mira Groupware (which can be found at http://miragroupware.org)
and I would like the Open Source community's input on a core part of
its architecture.

There are two options:

1. Client/Server

The user or company must set up their own Mira server and then
configure usernames and passwords for the users on that server. The
users can then set up that account on their client and, if the
authentication details are correct, they will have access to the Mira
server and be able to access the relevant Workplaces (project
management areas) on that server according to their role.

There are several advantages to this approach such as the data,
accounts and the like being controlled by the company or users, but
the main disadvantage is that each user might have to set up several
accounts for different servers to access them (and maintaining this
account list might be a bit of a pain) and so this approach is not
very fluid.

2. Centralised Servers

This involves Mira investing in centralised servers which would store
all user authentication data and any Workplace data associated with
those accounts (so each Mira user would have ONE account to access all
of their Workplaces). None of the actual Workplace data would be
stored on these centralised servers, only the information identifying
the existance of these Workplaces and the users who have access to
them (and their roles, etc).

This approach is more user-friendly than #1 but involves financial
investment by the Mira team and the possible disruption and decrease
in productivity of the users if the centralised Mira servers were to
go down, because all of the Mira clients would have nothing to contact
and would be useless. Also, if the Mira team ran out of money to fund
the server hosting, the whole project would die and Mira's users would
be left out in the cold.

--

Now, the dilemma is that we cannot decide which of these two core
authentication and Workplace management models to choose because each
has its own advantages and disadvantages.

I'd like your opinion on which model you think is best and why. Please
either reply here, send me an email at j_k9 [at] wolphination.com or
vote in the poll (and possibly add a comment) on Mira's forum:
http://miragroupware.org/forums/index.php?topic=21.0

Thank you,

-Max (a.k.a. J_K9)