If there will be a fork on BTC to the core and the big blog version. That means 2 blockchains.
Which wallet should i use to be able to get the also the coins on the other fork (the big blocks one?)
I read somewhere that some wallets (by wallet i mean something like armory or electrum, multibit etc.)
will not allow me to "extract" the coins from the other chain...?
Is this possible or is it some hoax and whatever wallet i use i will NOT be prohibited to acces the coins on the other chain?
Electrum can be used. Here is a detailed document on how to 'extract' coins from the other fork.
http://docs.electrum.org/en/latest/hardfork.html
People were prepared for the fork months back, when BTU seemed to be getting traction.