I don't have a means to watch Shiki as can't find it on a streaming service so I'll have to pass. When a date get's settled for Garden of Sinners though I'll join in on that one. I enjoyed those films and have been looking for an excuse to rewatch them. The main character being called Shiki is a strong coincidence.
I have Ping Pong scheduled for October, and Ergo Proxy for November, nothing for December yet but will probably decide that later on. dates for the others aren't set yet, will see if any other regular simulwatches get set so I can work around them.
Garden of Sinners is part of the regular schedule I think, I'd join to watch it though, I think they'd make for good rewatches.