What a nice welcome, thanks everyone!

Great advice, Kevin, thanks for your reply!

As for the substrate issue, I'm using (washed) sand that 'Argos' sell as play-sand.
It's been used successfully with axolotls, so I presume it's safe for ACFs.

I have a large garden that has been 'wild' for the last 10 years and totally organic, so earthworms, etc are plentiful.
Watering a patch of shaded ground, then covering it over in a sheet of black plastic overnight really does the trick!
I must sort out a small wormery soon.....
Also, I'm lucky in that there's a pet-shop in the next street that sells a variety of live food.

As for the ghost shrimp, despite them being really nice little fellas in their own right, they are only really in the tank to provide me with entertainment whilst the tank cycles (and to help it cycle).
I'm sure they'll be a tasty snack for a frog......bon appetite!

Thanks once again