Making your own research would always bring more relevant results as they are taken from your market and with your target audience. First of all check the Reseller Plans of as many companies as you can and see what they offer in their packages. From the general picture dissolve into features. Now make your research for the features, where can you get them, what are the prices, do they have a high demand and, of course, if you can afford to include them in your plans while still keeping a good price, both for you and the client.
It all comes down to your budget and how fast you are looking to make a revenue. You can go ahead and offer free Private DNS, WHM, SSL, SSH, billing software, merchant account, affordable domains etc. but if you cannot sustain that business model you will soon give up and disappear like many before you. Don't be one of "those" guys