HP....i would suggest that with a customer base of around 100 that there are 4 key issues:-
1. Do you want to encourage them all to talk together on a G community. If you think of it as a G controlled forum then that is a good comparison. If what you want to do is just to make technical details, help files, statistics and so on available then a blog/normal website might be more appropriate.
2. If a community works well and with such a small base then it might present a formidable barrier to entry for competitors. Effectively it becomes like a members club. You can also make them invitation only so you control entry.
3. If your industry sector lends itself to visuals, image, infographics, posters then this is good. They display really well and impressively.
4.It could be that a good idea to start the community slowly, tie it in to your other G properties,use it as another badge of trust for G.....then after a month or so with only a small number of "members" let it lie quiet until you can judge how successful this is in the longer term. Think of it as a banker.
Just suggestions...but hope they are useful.