Finally joined Collectors Society

I finally joined today, paid the membership dues and am anxiously awaiting the package with my five free grading coupons. I'll be sending in two 1921-D Walking Liberty halves - the only remaining "No Coin" in my long set - and hoping for a "real" grade on both. One is a (my opinion) F-15 that I recently bought; the other is a (also my opinion) G-6 that I found in a dealer's "junk silver" box years ago for 4x face value. Haven't decided what to use the other three coupons on; Silver Eagle anniversary set? 1889 gold $1 and $2.5 and 1814 half dollar?