Why not just drain a good portion of water and slide the tank forward and put the sump in from the back? Looks wide open to me. Seems safer, and less work
To be honest I'm afraid to move the thing. It's been there for about 14 years and I don't want to disturb anything that's settled in to position, so to speak. Also, when we had hard wood floors installed they actually trimmed around the bottom of the tank, so I'd have to rip that out to move it. I will be emptying about 30% of the water before I do this though so I think all will be fine.