Update and...decisions, decisions

As many of you know, we are expecting our 18th  child and we are now about 5 weeks away from delivery!  I'll sure tell you that no matter how many times we do this, the nerves are still there.  Christi has had a pretty good pregnancy and we are looking forward to greeting this new little one.  We are now at the point where we are discussing names and since she let me have Nathaniel, even though she really didn't like the name, Christi is going to get the final say on this one.  We don't know the sex yet, but we've been tossing Quinn and Zane (girl and boy, respectively) around.  We're still working on it.  The Doctor knows the gender, so if we can't stand the suspense, all Christi has to do is make a call and we can find out.  Either way is OK by me.  This being our 18th, and following our own tradition of naming, we face the problem of running out of letters for the first name.  It's always been our "thing" that we not repeat letters of the alphabet, and so far we have used A, B, C, D, E, G, H, J, K, L, M, N, R, S, T, V and W.  It makes it kind of hard to come up with a good name.  We also try to not use very common names, since my name is so popular, I always had several Davids in almost every class I was ever in.  Everywhere I work, Daves galore!  My father also made me promise not to name anyone after him (he didn't like his name, Homer) and we don't have any family names that some like to use.  Although we do try to honor our family members with the middle names, we also want the kids to have names they won't hate when they grow up.  So, name choice still in progress.  Any suggestions?