Range Boxes...
Mama Chay--Re: 3 gun range box: What ails putting only 3 guns into a 4- or 5-gun box? They're a little further apart, easier to get at, etc, etc. The 5 gun box isn't that much bigger than a 3 gunner, IMHO.
Also, there is that beginner factor you mention--What is there to prevent you from buying another gun later and wanting to haul 4 guns to the range? At that point the larger box would be really nice to already have.
As to looking cheesy--well, I shoot bullseye league, have seen hundreds of range boxes, and have yet to see one that looks exactly cool and classy. A range box is what it is, and it is NOT a Porche 911, for example. What I'm saying is, get a range box that does exactly what you want, and to heck with looks, or, for that matter, anybody else's opinion.
BTW, while you're at it, you'll find the inside-the-box spotting 'scope mount to be very useful, so you might want to pick one of those up if the box you buy doesn't come with one. And, of course, the 'scope that goes on the mount.
FWIW, I practice for league @ my local shooting club, and the usual reaction by non-bullseye shooters is, "Wow, is that ever a handy, good-idea box! Where can I get one??"
Come to think of it, my own range box has 4 slots, and I use it for my 3 bullseye guns. Never had any sort of problem as a result.
While I'm at it, welcome to TFL!