This looks awesome! You have a lot of initiative and I am glad to have your help!
Procedurally, what I'd like to do is get the code setup in our repository and give you commit access. You'll need to get a Novell Forge account, just visit this page and you'll see the create account link at the bottom. Then send me an email with a zip of the code and tell me your Novell username. I'll create a branch for this project, check in the code, and send you the url so you can checkout and continue working on it. I hope :-)
When I get the code from you I may stub out additional class library projects in the solution where we can encapsulate the platform differences. Then maybe I can help on the windows side of the house with the IIS configuration code. Even if you don't keep going from here, its a good start and getting the ball rolling is often the hardest part and you've done that. I'll put no pressure on you but welcome any additional help you may find time for.
The current release packages have a lot of redundancy, there is very little difference between them, mainly just a few dll differences. For embedding in the installer I will package without any duplication. core package for ms sql, separate zips for the data dlls for the other dbs and separate zip for the web ui dlls for mono (which I compile on linux).
What I'd like it to do is make it look for an existing user.config and if not present create it and put the connection string there. On upgrades we leave this file alone so it doesn't lose its connection string.