I would like to invest in a light kit (And a flashgun as well) for portraits. Headshots, kids, etc.

I found this kit on B&H and it's in my price range. Has anyone used this light kit or have any other affordable solutions? Impact Two Monolight Kit - 200 Total Watt/Seconds EX100A-2KI B&H

I have a 42" 5 in 1 reflector that I could use with the set up.

I'm shooting with a Canon XSi and a 50mm f/1.8. Is there a better lens that I should invest in for portraits?

Any advice would be greatly appreciated!
Thanks!