Try to have a look at eUKhost reseller web hosting solutions.
They do NOT allow overselling on any of their reseller hosting plans.
You will have nice advantages dealing with them (according to my personal experience).
M6.net has a long history in delivering Windows services and it's positive. More than 10 years of being on the top means much for me.
Uptime is high and their services are popular among those who run Windows-based business.
Sorry i don't have any experience with this company.
I suggest to Goresellers.com .Here i found the two reseller packages at cheap price. Through this you can get the domain names at cheap price & sell it to others.