Shopping for a new theme for the long term.

I have about 40 subsites built with a theme that is undergoing a major revision, which means I will have to make some manual fixes to each site. I realize this can happen when a major update comes.

My question is: with the Upfront theme designer, do we only have the three current Upfront themes to choose from? I will need tovreproduce what I have already created for my current customers. Here's an example of my template (Created by New Blog Templates plugin):

I need to make a good choice now to select a theme that will be good for the rest of the foreseeable future because when I have hundreds of subsites, I wouldn't be able to individually fix each one if the theme is discontinued or a major update comes.

Looking for some advice. Thanks, Joe.