For lower cost option the SB700 is best option that gives you full control including commander function. Right now they are $240 refurbished from Nikonusa. That's a very good price. Or new on sale for $300 again good price for capabilities. Besides guide number it can only control 2 groups vs 3 wit SB900 and 910.
I have 600's, 700's, 900's and 1 SB5000, and 4 light set sbr200's, in cls flash units. Bunch of older units too.
The 300, 400, and 500 never owned one. But low powered, small though. The r200s I got in R1 kit, and picked up 2 extra lights. Lenses can hold up to 4 of them on the ring. Though a ring can mount 8 if off lens.