Here is what I found and if anyone from Symantec can confirm or deny this that would be a big help
I looks like even though my SEPM console is MR4MP2 and is capable of doing an install from a HTTP source I can only install MR4 from the SEPM console. Once I am up to MR4 I can then use a HTTP server to go from MR4 to MR4MP2. Still testing here but that seems to be the case at least. As soon as I switched to install from SEPM the MR4 upgrade went immediatly.