Pen testing utility tool development (SSH)

I need some one of acquitted experience to create a SSH mass login attempt tool (A mass brute force tool is the only thing similar). I would prefer if it was written in C but i do not care about language used as long is it executes very quickly. I need a tool to try to log into a ssh device and try to use given logins to find devices with the given logins and if it finds a successful login and is sighed into a device it needs to be able to tell if it has truly logged in. As it will obtain any given prompt or try to execute a basic command. To prove it is a valid device. I can explain in more detail if needed. I need this tool for insuring my network is not vulnerable to common/default logins (its quite large). Also so i can get some statistics for analyzing how many vulnerable devices there may bee out there. I can provide common SSH logins for testing purposes. Budget is adjustable depending on how effective and efficient the tool is.