Why not extend your stay another year before going to Laos? You can apply for a re-entry permit and you'll still have a permission to stay for a year. It's well worth 1,900 baht.
The TM30 is not a certificate of residence. It's your registered adress in your province. The certificate of residence is something else and you apply for it at immigration.
If you arrive on a 90 days Non-O, just concentrate on opening a bank account. Apply for a certificate of residence at the local immigration office,and go bank hunting. You don't need an agent. Just a waste of money. The correct type of visa and the certificate of residence are imo most important.