What I ended up with, were to run a virtual installation of Smoothwall as the virtual gateway and then a sme1 as the "production" and sme2 at the test server, and then also a virtual Windows 2000 as the "remote controlled virtual Windows client" for admin and other purposes.
This gave all the options of the Smoothwall togeteher with all the options of the Sme server, and a Windows client, pluss actually also a Asterisk server, all running in one gateway box.
To my surprice it all runned completely stable for a year or so. (But only as a home server with rather little load.) I expect it to be to complex and to coplicated but, ther were less bugs than for my sme server only, actually no bugs at all, and completely stable.
The nice thing with the "thin as posible" host system, is that there is little that needs to be upgraded, and that can be broken. (All ip trafic enters "directely" to the virtual installations via bridging, and the host does in some way not "see" the traffic, passing trough, at all. The host system does not need to have a ip at all, so there is nothing to access or attack.)(At least it were my idea when I made this setup.)
Of cource it would be nice if someone knew how to make the the 8.0 as the host as well, so that there is some options ..