As far as the LCD spin out goes, I only put that there as I've not used a 20x4 display so wasn't 100% sure they were all identical. I'd guessed they were as the backpacks work on those two, but safer to have the OP make sure. 
Hopefully he'll report back if it's worked for him. I know some people can get tremely frustrated when things don't work and get the 'it's no good, I'm fed up, it's rubbish' red mist. I have a couple of mates with low patience levels like that. 