I always adored Gideon, but we have a girl and DH vetoed it anyway. Could be shortened to 'gid' or 'deon'. I also like Solomon. Funny, I'm not religious at all, just like biblical names. Good Luck. If you find a name you like, but you're not sold on, I've seen some sites on the web that will give you "if you like the name 'x', you love these" suggestions.
We had such trouble naming DS#2! I totally understand. It was a lot easier for me once I gave up on trying to find the perfect, unique name. I focused on finding a name that "fit" with DS#1. I, too, wanted a name that lent itself to good nickname but had longer full name. Boys names are difficult! Some of the ones on our list that we didn't use, but that I like a lot:
I had fun browsing baby name sites by country...Finnish and Icelandic names are particularly fun!