When running the 810AV in stereo, they rate it at 2X8 ohms which would be a 4 ohm load. Your Neo should also be 4 ohms. This would give you a 2 ohm load. According to Ampeg's website, the 4Pro can run at 2 ohms.
"If you don't want the truth don't ask. Make up your own like everyone else does". (Michael Pare as Eddie Wilson/Joe West in Eddie and The Cruisers II).