I all, I have some questions about creating my viv for leucs.

I have bought most of the items I need, but I have some questions:

1. I bought silicone sealant (unibond brand "hygienic kitchen sealant") because it says it is not mould resistant and doesnt have a fungicide. Is there more that I need to worry about it containing?

2. I'm struggling to get hold of a fan that I can use in the top of my viv - I can find 12v pc fans without a way to power them, or 230v mains fans with bare (!) connectors. What do you guys use?

3. I'm trying to decide on the best way to get the plants planted off the floor of the viv. The best way I've seen this done is using expanded foam, but I'm worried about getting this wrong. Any suggestions?

4. If I do go the expanded foam route, should I be using it to add to the exo-terra background that I already have? or is it better to start from scratch?

Just so you have an idea of what I have - its an 18x18x24" tank (exo-terra brand) I have a large hollow log of cork with a bend in it that has already been baked, and the following plants:

a bromeliad I found in a diy shop
Neoregelia olens
Ficus pumila
philodendron scandens
tropical pillow moss
java moss
and Im considering getting a peace lily, maybe an orchid or a mimosa pudica.

Thanks for the advice!