Good Substrates - which bark??

[cutelittlebuttons]

Hey,
i'm pretty much as new as you can get to tortoises and we've converted the greenhouse into a home for a pair of girls as they can't get any uv light in there they have a ramp to get outside into a little fenced off area on cold nights they come inside in a tortoise *table* (well our homemade one) though.
the whole of the greenhouse floor is covered in top soil (from b&q) and so we can get in we put down some slabs - when they come outside the floor is just slabs too. but to make it more interesting we thought that maybe adding more substrates would be good? i was thinking like bark... i heard coconut bark and orchid bark is good. which one is better? i've been looking on surrey pet supplies and found these
http://www.surreypetsupplies.co.uk/t-rex-coconut-bark.html

http://www.surreypetsupplies.co.uk/orchid-bark-coarse.html

they're only going to have one bark area so it will be either one of these, don't really want to mix them
anyone got experience with this? or any other good substrates? thank you!! x

 

[DeanS]

Some use both...but most lean towards coco coir.