Hi Jerry,
The mortar im using is building, sharp sand and cement on a ratio of 3:1:1 all materials im using which i have lying around from doing patio including the bricks haven't used any fire bricks or mortar just making use of what ive got.
Totally intend to use wood as well as charcoal, the metal skewer stands are 3mm thick they could bend under the heat, im unsure ill keep you posted on that one.