Designing a man cave in my head/paper

Not really a RPG post.  Kinda of.

So at home we are currently renovating what feels like our entire house.  While we have been doing it, I've started to think about getting myself a man cave.  Note:  I don't have a garage, and I don't have room for one.  I do have an office, which is kinda of a shared space, that's mostly filled with some of my random crap, and files, and more paper, and semi drawn maps.  You get the gist.

In the basement, under the stairs leading up to the new kitchen there is this odd rectangular room, that seems to be an ideal place to put random Shane stuff. I'm going to say its like 12 feet by 8 feet wide giver take.

What I'm trying to figure out is how to get a gaming table, a sorta bookshelf/place to put a record player and LPs (which I might have to build... oooh another project).  Some guitars, an amp, and if at all possible maybe a bit of a music station.  Unfortunately there's NOT going to be enough room.

Here's a terrible doodle, complete with cross hatching.