Hello terataz
Regarding your inquiries.
We are planning to use Centova reseller API to integrate streaming into our current platform.
If you have a customized platform, you're far better of using your current development contractor, however if you're using off-the-shelf solutions, you probably should look for someone specialized in that specific product as opposed to someone that knows about Centova Cast. I said this because the Centova Cast API is really not that complicated, and any experienced programer should be able to use it without too much effort.
We don't want to run the streaming server or install Centova ourself, but use a solid and reliable third party
hosting provider with experience in running Centova and knowledge on using its API.
If what you need is a reseller account, then yes you should look for a suited hosting provider. However if you have your own servers, but you need someone to take care of the installation and maintenance, you can purchase installation and admin services directly from Centova Cast.
Many providers seems to know only the basic uses of Centova.
Anyone in particular you would recommend?
We're not allowed to recommend hosting providers, but you could refer to a well known hosting community like web hosting talk for that kind of question.
http://www.webhostingtalk.com/Hope this info helps.