"Johnny is a fantastic signing for the club. He has played a lot of football at League One level and there were a number of clubs chasing him so it's nice that he has chosen to come to us," said the gaffer.
"We never really thought that we had a chance of getting him but with the situation at Stockport and the new consortium coming in, I think he was just looking for a change.
"We got a whisper from somebody who said that he might be available and it just went from there."
Moore added: "I've known Johnny for a long time. He can play at centre-back or right-back. He is aggressive, a good talker and I think he is a fantastic signing for the club when you look at the other sides who were after him.
"Johnny has shown a willingness to come aboard and has seen the ambition of the club. Everybody who you speak to in football who knows Johnny speak very highly of him so I think we have pulled off a major coup in getting him."
MillersMAD understands Moore is also very close to finalising a contract to sign Mark Bradley, released by Walsall, but other clubs including Shrewsbury Town are also talking to the midfielder.
Moore concluded in todays Star: "I won't be far off with my final squad now if we can add Mark to the midfield."