Can we have two Shopping cart transaction type?

Hi SRM Gurus,

I am having a doubt.Please clarify

Is it possible to include two transaction types for shopping cart?The follow on documents  corresponding to each one is different.

Transaction types  of shopping cart can be the main criteria for determining approval process. In the Front end, how user can choose the transaction type, i.e whether in the User Interface screen, transaction type will appear for choosing? Or any customized program is required to include transaction types in the shopping cart screen.

Thanks in advance,

Ramkumar