Just one thing. In a small studio space you have I think 750W is overkill. You'll struggle to get power low enough!
I have been looking at getting 400 - 500w Heads x 2, with an additional 250w later on, In UK the most popular are Bowens & Elinchrom ( 500 Bowens & 400 Elinchrom )
You should listen to fmw he knows what he is writing about. With flash there is no such thing as too much power. You can always reduce the output. 1/16 or 1/32 power is available on all decent strobe systems.
Just so you know! I found your post very informative. Thanks!Steve - fmw has generously given you some great information. I am a studio photographer, and would like to help too. I see your last question but I'm afraid I don't understand what you mean. Can you explain the question a little? What do you mean by standard and digital ranges?