I am wicked surprised that some rabid Rutan fan hasn't posted a rant about the virtues of the Long EZ and how you all "just don't get it." The Long EZ has had a controversial past and a large percentage of them are now grounded, or have been ground up, so, given your selection of only the two, I'd definitley say "buy a Grumman."
However, if you're not going to be flying that Grumman more than 120 hours a year: RENT!!! The advantages of renting over owning are many, including gaining experience in many different types with many different instrument layouts and avionics, and NO nickle & diming maintenance issues, storgage fees, insurance, and having a big chunk of your finances tied up in something your partner (wife) is ambivalent (at best) about. It's nice to have that dream of owning your own plane, so don't give up on it, just put it on hold until you can realistically commit to flying at least 10 hours every month. Hopefully by then you'll have a better idea of what the best plane for you is, and what you'll want in the panel.