Configuring L2L tunnels or remote access is very simple in an ASA. They have GUI based step by step instruction on deploying both these tunnels.
I haven't understood your question on you customers not seeing your internal network--Actually L2L would mean that the remote customer would be acccessing one of your internal networks atleast- is there anything else that you want.
Your second query can be implemented easily.
THis page would give you configuration examples for your scenario http://www.cisco.com/en/US/products/ps6120/prod_configuration_examples_list.html
-Hoogen
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