Which Weighted Balls to buy?

I am about to buy a set of weighted balls and would like some recommendation as to which balls I should buy.
I mean, which brand - Worth, Markwort, …?
By the way, do you all recommend the Wolforth DVD? Sounds good, but the price is pretty high as well…

I got a set (4,5,6) from baseballfit.com and love them

I’m pretty sure there different what’s pictured, but they’re actually nicer than what I expected.

really nice cover, and stiches.

It was actually one of the fewer sites I found with a 4oz and 6oz ball.