Recommended Professional Theme Providers

As the topic implies, I’m looking to populate my available free/premium themes with the professionally done themes of at least one or two 3rd party authors.

Without any actual experience with the few that I’ve found, I’m hoping to get a few testimonials from the community. I’m assuming many of you have been in the same position I’m in now. Getting ready to launch your multisite network, and gathering a diverse collection of themes.

http://www.themeskingdom.com/

Cost: $29/year ($14 w/discount code)

http://inkthemes.com

Cost: $147 first month, $15 each month afterwards

https://www.elegantthemes.com

Cost: $89/year (w/plugins) $39/year (w/o plugins)

http://www.wpexplorer.com

Cost: $45/per theme

Beyond just the cost, from these theme providers, or others you have used yourself or simply read about, how has the integration of the themes been for you? Any probably with the theme options interface? Did you notice any excessively branding? Did they come with a GNU/GPL license? Would you recommend them?

Does anyone have any general recommendations for this stage of development of my network? I realize much will depend on my needs, but I’m still open to other ways of populating my available themes.

So far, I’m thinking I could use themekingdom themes for my free themes, and perhaps elegantthemes for my premium selections. The theme options interface for the latter looked appealing, but again, beyond the screenshots I know nothing about either.