Hi John, this may not be the answer you are looking for, but wanted to bring a perspective.
In your early days just after the launch or to get to 100/150 customers, it is highly recommended to focus on 1 or 2 channels at max.
Also, it is recommneded not to automate social media till you know what's working. It's best to manually share content/offers etc in the first 1/2 months to see which platforms are working and what type of content increases engagement and traffic.
Also, here are some pointers to choose couple of social networks which are specific to your type of business and your target market.
Here's a glimpse at the social networks which brought in most sales by category of products:
Let's look at conversion now. Here are the conversion % of visit to purchase from traffic from social networks: 
As you look at the above data, you can choose the social network(s) which can bring you traction in the best manner.
Source of images: Which Social Media Platform... Most Sales? [Infographic]