I don't know if you're open to it, but I'm pretty partial to Microsoft .Net 
framework and platform stack.

Pretty much everything from the front end to the back end is totally 
integrated. It is a wonderful developer/designer experience.

Additionally, these tools are all available for NO additional cost to you as UMN 
staff. But you have to ask for Visual Studio 2010 professional edition from 
[log in to unmask] because they don't list it on 
https://download.software.umn.edu/ any more (now it is in netfiles)

In particular the combination of the powerful Visual Studio 2010 IDE, .Net 
framework 4.0, Entity Framework or NHibernate, and ASP.Net MVC 2 are a 
formidable offering. Again all of this has NO added cost to you. It's all free.

There are a ton of IOC and ORM offerings in the .Net space so you can easily 
choose one to your liking.

MEF and Unity (dependency injector) are fairly cool too.

Support, Training, Developer Communities, Books, knowledgeable consultants, 
campus expertise, 3rd party vendors are all available. 

One configuration you might want to look at to get started (where someone 
else has done the work of picking the pieces for you) would be to look at 
http://SharpArchitecture.net/ which is stored on GitHub at 
http://github.com/codai/Sharp-Architecture

Before you choose Ruby/Rails I suggest you investigate deployment difficulties.