is that a pretty good indicator
Yes.
If you add contribs (addons) from the SME repositories, all should be well.
If not, search the forums for answers, or ask the developer/maintainer of the contrib.
BUT - remember, keep is simple. Your server should just be a server, not a work-station, media box or games PC as well.
Since you want your local IT shop to supply the server, if they can run up SME 8.0 (or 8.1 if it is available) then that box should do for your requirements.
If you want it as just a server, it only needs 1 network card.
For a Gateway and Server, it needs 2 network cards.
I suggest it is time to get on with it - or as has been said by 11-year-olds all over the world, "Suck it and see"..
Cheers
Ian