Could anyone explain me please in average Joe words how can I purchase MC, does it have it's own client, where my MCs would be stored etc,e tc as I don't understand a shit about this but would test my luck investing few satoshis.
Right now you can do OTC purchases via this
order book. In a few days there will be a distributed exchange build in to at least two wallets so that you can buy Mastercoins using zero trust. This also answers your other question; yes there are wallets (under heavy development). Your Mastercoins are stored on a normal Bitcoin address that you pick choose using a normal client.
For more info check the
wiki.