hit up Gordi. He lives there.
Missed this one!
Actually I live in Nara, about half an hour by train from Osaka, but close enough...
There used to be a New Japan shop in Metro Hotel in the Doutonbori area of Namba, but I think it's closed now. Mr. Hito had a small shop, also in Namba, but he passed away in 2010 (RIP, my friend). As far as I know, there are sadly no puroresu shops in Osaka any more.
Bodymaker Colosseum is the new name for Osaka Prefectural Gymnasium. It's also in Namba. Lots of cheap hotels there.
Definitely recommend going to an Osaka Pro show (in Umeda) and a Kuuga Produce show (in the old Osaka Pro arena in, you guessed it, Namba) while you're here!