Holy moly that's a lot of basil!! Great harvest! Make more pesto with different flavors!! Maybe do one with other herbs kind of like a chimmichurri you could use as a marinade- maybe some balsamic and onion?? Hmm...your problem is not a bad one to have :)
I made some with walnuts and asiago, and some with pinenuts and parmesan, and some with lemon peel. I ended up sharing some with a friend. I suspect I may have more in Fridays CSA box...a managable amount. I like your marinade idea.