Is there a full length straight play version Charlie and the Chocolate Factory, other than the one by Richard George.  The dialogue in that one is amateur sounding and not at all appealing, though the thought of doing the show is.  Doing a musical version is not an option.

I've done the George version.  It's short (no intermission; about an hour, but we stuck an intermission in arbitrarily).  You're right - the dialogue is not that great. There were some comments during rehearsals along the lines of "real people don't talk that way, even if they are in England..."  The play relies (too much, IMO) on a narrator to get things going and to transition from scene to scene at the start of the story, but then the narrator just sort of disappears.

The play does keep closely to the book once things get going in the Chocolate Factory.  All the original oompa-loompa poems are included verbatim. (We had a cast of oompa-loompas come out and recite them.)  But those are about the only good things I can say about it.

The script includes a short note from Mr. Dahl, indicating that George's version was the one that he authorized.  It also mentions that the play was written as a school play - George originally wrote it for his 6th grade students. (You can find this on amazon's "peek inside" feature.)

I, too, wish there were a good full-length non-musical adaption of the book.