Single Page Ecommerce

Good day Folks ,

Ive been banging my head on the desk for some days now trying to figure this out for a client. They need a sort of Purchase order so that a client can log into a secure page ( easy enough ) and fill out a calculated form , with Purchase order number , address, phone number etc and then it is emailed to owner of the company and also lets the person know who filled it out that its been sent.

He would like it to look similar to this ..

https://forums.adobe.com/servlet/JiveServlet/download/2603753-39203/Purchase%20Order.pdf

This is a PDF based PO from with drop downs for items.

I have looked at Form software ( both on and off WP ) , PO software, Spread sheet makers and Im at a loss. Can anyone think of a way to do this efficiently ? Also the base item(s) have a number of addons to increase the price. Like Widget a is $100, Paint widget A +$25, Make Widget A Bigger +$10 and so on .

HELLLLLLLLP 🙂

Thank you all in advance who reply – Cheers – B