I need to setup users so that they can select another sites trunks to make calls. This is Not for a Toll bypass as both sites are in the same area code but to satisfy some call accounting requirements. Is it possible to select my SPNet trunks via their access code (803) followed by the Site ID followed by the remote DID 19 and then the number that I want to dial?

Yes, it will follow sites A config as it will pass the cli over the SPnet and then site A will deal with the call as per normal.

OK I tested doing the manual dialing and it made the call, now I am going to try and build that into a speed dial followed by the number that they want to call, I would like to set the CLI for each call. Anybody know how the MACR button feature works?

You should be able to set up your NLCR so that it automatically select the other trunks depending on what is dialed.

The cli is fixed per extension, unless you use the tclip feature.
The macr key let's you combine 2 personal speed dials together to create 1 long dial string possibly with feature codes

An easy way to do this is to set up some virtual extensions on each site with forward all to the local trunk group. Setup the CLI you want to present on each virtual extension.

Simply dial the site B extension from site A and you will get dial tone from the trunks on site B and the call will present the CLI associated with the virtual extension.

VIBob I tried your suggestion, I can call the virtual extension and get dial tone but it is not accepting what I am dialing.
If I enter a number in 5.15.6 it will dial that number.

You have to turn on the Intercom External Forward. Also, make sure these virtuals do not have either EXT or MBX blocks assigned as you won't want them to be reached via the SVMi.