I have to create a custom module - can i do this with suitecrm?

Hi! Here is what i have to do:

I need to make a module with some fields required to make an order. I need a fields with a products which users can add with + button or something.
I dont want to create a products in products module - just a dynamic fields (abillity to next product with +). It will send a pdf template.

It will be best if it can add a group of fields and total ammount.

Please use Quotes/Invoices modules for this.

As Will has said the Quotes/Invoices module pretty much does everything you asked for. If it is something different you require then you will have to custom code it or pay someone to code it for you.