To my knowledge, Streamray (cams.com) has an option to let you integrate your api that you can implement to your layout (need a merchant acct which you have) and their affiliate guys can help you set that up.
Streamate is very popular and a lot of the big dogs us it, but from what I understand they only provide a whitelabel they build themselves on your domain through their dns but you have apply to their merchant through them. You also have to pretty much sign over the domain to them by changing the ownership in your registrar to their info so their merchant recognizes the site as part of their setup or something like that.
If you have your own software already, I think verotel has plans specifically for webcams, if you aren't in too deep with ccbll, or they wont help you support wise, you could look into that. I hear verotel is helpful with installation etc.
Good Luck
