I will absolutely not send the engine to a builder who's many miles away as you have no control over him should things do go bad. It would always be your word against them as shops NEVER EVER take a blame should things do go south
Make sure the replacement engine is healthy (oil analysis), spend $3000 on replacing all the week links including but not limiting to valve stems, RB, TC, the coolant pipes, all hoses, vacuum lines, coils/plugs, thermostat etc
If you are not happy with it sell it but selling with a rebuilt engine sounds terrible from resale point of view especially where it was rebuilt by a shop known to only few internet users
Hope that helps