Simple Invoices - Forum

I made new template for simpleinvoices, but I found serious problem for me.
The attribute: $invoice.type_id is in all mean 2
I switch other style for invoice and nothing is change.
For this problem, I cannot change the design for different invoice styles.
Other problem serious for me too.
When I change invoice style from one to other and then back. Invoice hasn't the same id but id +1.
Example invoice with id 33. I change style from invoice to qoute, then back and invoice for this id is 34. 33 is missing in db.
In this case I create custom field and I use it as invoice ID.
When somebody print the invoice and check the invoice in past from this data IDs can be different. (Most of people change invoice type and then take it back)