Ive been in photography for 10 years, and I prefer to do work on location outside, so I use natural light when ever I can. I have taken a lighting technique class and I use my external flashes all manually.
I have a studio, good for the bad weather days, and I've been using 4 or 5 flashes to do the lighting. This works great, but it also eats up batteries with each flash using 4AA's. I dont use the studio that much because of doing location work, but I'm starting to focus more on ballet and gymnastics portraits, so I would like to get some strobes.
But I don't really know a thing when it comes to strobes. The different brands, the terms, etc. I think you need a power pack that looks a bit like a car battery with lights, but I'm not sure.
** So I am hoping you all could suggest a couple strobes to get that wont break the bank.
I would like something that will let me get an exposure at iso 100 around F8, allow me to change the light output easily and have at least a few stops to choose from, *I dont want to have to move the light closer or further away to get the same affect* and allow me to take pictures relatively fast after each other. Thats one of the biggest drawbacks with my current flashes, I have to wait a couple seconds between shots for them to charge up.
Idealy, I would like to have 5 flashes, 2 for the background *still perplexes me how to get the 2 flashes in the back to shine evenly over the background with out the spots closer to the flash being brighter and the light facing away till they meet in the center*, a left and right light and a fill flash in the center.
But to start off, I think Ill just get the left and right strobes and play with the position of them and a bounce sheet.
* I'm also not looking to spend more than $100 on the two, I'm thinking this part isn't realistic. Perhaps there will be a black friday sale online? 
I appreciate any help and suggestions that are offered.

