All my lines are to be outgoing only, if I set up SP1 with a provider with 300 mins and SP2 with a secondary provider if SP1 gets to 300 mins will any additional minutes roll over to SP2? Also if SP1 goes down will SP2 take over.
The general answers to your two questions are no and no.
Regarding the first, how would the OBi know that you have used your 300 minutes of allocation?
As to the second, depending on what you mean by "goes down" you might have some success by putting SP1 and SP2 in a Trunk Group and sending outgoing calls to that. http://www.obihai.com/OBiDeviceAdminGuide#_Toc367543101
I have a commercial application, whom would I contact for more in depth support? I have a lot to learn about this product.
Read the Admin Guide slowly from cover to cover. Then repeat. Then repeat. By then you will know most of what the units can do.
For more you need to contact OBihai. This forum is primarily user to user.
If you don't understand something, just ask.
Here is an example of a Trunk Group:
http://www.obitalk.com/forum/index.php?topic=11329.0