Web Framework suggestions for a RIA type application for managing lab specimens

[rynt]

Hello all.

I'm Looking for suggestions for which Python web framework(e.g.
Django, Turbogears,etc.) would work best to develop a cross platform
browser based system to manage lab specimens.

Requirements are:
a. highly secure
b. run on internet or intranet
e. RDBMS read/write intensive
d. be able to work on-line or off-line (with automatic updates to db
when coming back on-line)
e. be able to print reports and labels using a variety of
printers(laser, deskjet, label printers)
f. have a rich set of desktop-like components

Perhaps a web based app isn't the way to go.  Arguments for and
against gratefully accepted.

Pros and Cons for any frameworks gratefully accepted.

Perhaps a framework isn't really what's needed here, but a combination
of different web components and technologies?

Anyway, I'm grateful for any ideas you may be able to give me.

Thanks
Ruben