I would not invest too much until I was into the space for a little while. Decisions I would have made about my sewing space when I first started out would not have been nearly as good as ones I made after I had a little more experience. Rather than put everything in there and then be sorry about something in the way it is laid out, I would put the minimum in and play around in there for a few weeks or so. I bet you have different thoughts after having used the space for a while.
Just my humble opinion...
Either way, enjoy it! What a great thing for your DH to do.