SMALL studio HIGH-KEY lighting on a budget!

Okay, so I'm going to attempt to have my cake and eat it too!

I'm not stranger to photography but studio-ish lighting and indoor photography isn't where my experience is. What I'm looking to do is get a quick little studio-setup in my apartment (it's a small studio) or just outside in the hall where there is a huge space and no one really walks. Both places have a white wall that if I blow enough light at, I can blow it out without needing a paper background.

The image below was taken of myself in my apartment (as was this one). I want to get this headshot workflow down but I'm wondering what other gear I need as I feel I need more lighting. My current lighting is: 1 580EXII, 1 270EXII, 1 60" silver reflective umbrella, 2 43" white shoot-through umbrellas, 2 Manfrotto lightstands both with umbrella clamps. I have Cowboy triggers that work amazingly for the price!

My non-lighting gear is: Vanguard carbon-fiber tripod, Canon 5DMk3, EF 70-200mm f/2.8 L IS USM, Sigma 50mm f/1.4 EX and Tamron 24-70mm f/2.8 VC.

What I'm looking to do is use the 70-200 to shoot f/8-11-ish portraits at the lowest ISO I can shoot at (currently it's about ISO 320, which is fine but ISO 50 is always nice!)

I'm looking at investing in a very nice studio strobe, but what are my Speedlight options? Amazon has some YongNuo flashes that are great for this sort of thing, I'd imagine. Cost less than Canon speedlights and I think I can get away with them versus a $1k studio strobe head if I have several of them, no?

Any input from experienced high-key photographers would be a plus, thanks! :)

- Jordan
http://www.flickr.com/photos/freshphotolive/
http://farm9.staticflickr.com/8058/8...8031aafa_c.jpg

IMHO, the attached photo and at the about page looks great! I ain't experienced high-key photographer but those YongNuo flashes are nice based from experience. I got one for myself as a second speedlight. At the time I bought my YongNuo was only about 1/7th of the Canon 580 EXII which I think is great. I made a side-by-side comaprison fo the YN560 and the 580EXII and at full power, they are indistinguishable but as I power down (1 -> 1/2 power), the YN560 was about -1/3 of a stop which I think is not bad.

I ain't sure if this helps or just a buzz.

Anyway, best wishes on your photography business.