I think Lennox is a cute name & love the idea of Lenny for a nn! But your dh is right it is a popular computer OS. Kind of like Windows for people who hate Windows, except there are no actual windows, but it is open source so you can do a lot with it. Everything has to be done via command line, though, unless you create your own window like shortcuts on the desktop. Lennox also takes up less space than Windows. I think most people view it as the os for smart people, haha. My dh LOVES Lennox and makes fun of me for using Windows all the time.
Anyway, it sounds like you're really leaning toward Lennox and I think you should go for it, if your dh agrees!
From my list, I think Aspen & Kaede are my faves. I really like Cortland, but with your LN, that obviously wouldn't work. Although, Phillip Phillips did win AI this year & his name was pretty catchy, lol.
Pax is latin for peace & I think Paxton would be a cute name
Cleo means joyfully happy, bundle of joy
Asher is a Hebrew name meaning happiness
Edwin means happy friend
Edmund means happy defender