Nikon strobist equipment, what off camera flash could I do with this?

This is stuff my friend and I have:
(1) 50mm 1.8G
(2) 35mm 1.8G
Nikon D7000 (has commander mode)
Nikon D3200 (has 24 megapixels with 12 bit raw files)
Nikon D5000, might sell it for more stuff though
(1) SB-600
(1) SB-80DX (my friend's really old speedlight that he never uses)
(2) Cowboy Studio Wireless Triggers
(-) big white cardboard (reflector)
A bunch of basic tripods, maybe use as stands for mounted equipment?
Lastly… 2 amateur photographers.

As you can see we don't really have much but wondering what equipment I can get to bounce off light like umbrellas. I don't know about the SB-80DX, maybe can be used as a slave? It is more powerful than the SB-600.

Added (1). Need softboxes too.

Added (2). @AskKan lol thanks

You have all this stuff and "we don't really have much" wow! What else do you want to have? A Phase One and still say you haven't got anything! You need an umbrella, a light stand and a flash in front of it. And a trigger but you already have that.

What are you trying to do? I mean, 3 cameras for 2 people seems like you have plenty.

Start taking pictures. Lots of them. One day, you will say - Wow, we need to take a picture, but can't until we get xxx. THATS when you need xxx.

I have an architectural photography business, shooting 5-10 houses a week, and I do it with a lot less stuff than you have.

Get some light stands… Flash brackets and a few years of study in off camera flash

The D7000 will control both those flashes in SU-4 commander mode. It will only control the SB-600 in i-TTL mode.

Get cheap manual flashes, like the Yongnuo YN-460 ($40 or so all over ebay) and a few more receivers. Most flashes that come with a stand will mount on a tripod, the downside is that most tripods won';t give you the height of a light stand. Light stands are cheap, get some. As for umbrellas and boxes and all that… That depends on what you want to do, how much money you have to spend, and personal preference. I tend to use umbrellas more than softboxes, you may prefer boxes to brollies.

Cowboy Studio has all this stuff… Except maybe the cheap manual flashes. Haven't looked for while.