Re: Iwata or Tozando Hakama
I wear cotton indigo dyed Hakama. For years, I've only worn Iwata brand. However, last year I bought a Tozando indigo dyed Hakama. I feel that lately the Tozando quality has been superior to Iwata. I see this in both the Tozando indigo dyed Hakama and their gi. Also, the Tozando prices are a bit lower.
That being said, I bought the black cotton Tozando Hakama that you linked as a gift for one of our students after passing his Shodan exam (he is 73 years old BTW) last year. I have also seen the similar Iwata black cotton Hakama. Although I haven't worn it or folded it, visually the Iwata brand looks 'better' in terms of the fabric and pleating than the Tozando.
Another comment, the size of the kanji/katakana (if you choose to have embroidery) on the Iwata is larger than the Tozando. Although, Tozando has more color and style choices.
I don't think you'll go wrong with either choice.