[cypher]

Kaytee clean & cosy is a really good substrate so that would be fine.
Some people do use coir in a small part of the cage for variety but it isn't suitable as a main substrate, personally I wouldn't recommend it as it can get damp & doesn't dry out like substrate so you could potentially end up with mould issues.
Rodipet does deliver to the uk & the cost is quite reasonable really, they do some good houses, I really like the wooden ones with granite lids, although any wood does need to be painted with Plastikote water based enamel to pee proof it you could use the clear one if you wanted a natural look.
Cork tubes & tunnels are great for natural looking cages or any cage for that matter, coconuts make good hideouts too & also have a nice natural look.