Advice on Design of Ordering System App with Multiple Forms

[DAllen365]

Hey all, I am working to design a build a solution with PowerApps and Power Automate that is a digital ordering system.  It is comprised of 7 different simplistic forms of company merchandise.  These orders will then be reviewed, sent to the vendor, received and shipped to the relevant store.  My questions revolve around the design of the Power App.  

1. How many apps?  I really envision one app "The Ordering App", and you choose order form you want, it loads that form, you fill it out and save.  Each form has different metadata so would need to go to different SharePoint lists.  Can I do this in one where each form screen can save to a different SP list?   Of course I could just build 7 apps and it would be mapped, but one app seems better.  Thoughts?
2. They want users to have save as draft / submit ability, so now I need a way to see existing orders to open drafts.  This obviously complicates things so how do I do that for 7 forms in one app? 
3. Another requirement is that they want to have an easy way to update prices and offered inventory for different forms.  They do not need to track amount of inventory, but just what items are available and their price per unit.  To make the form easy to use, I am thinking to use like repeating controls.  Can I have a lookup feed into a repeater like that, where when you add a line, you choose a product dropdown then a picture and price per unity loads, and you just specify the needed qty and then it shows a subtotal price calculation.  

These order forms range from ordering clothes racks to business cards, nametags and other merch.  These are all separate flat Excel files today so its exciting to turn these into very visual forms, but I would like some advice on how to structure it.  Let me know if I need to clarify anything.  Thanks in advance! 

[v-bofeng-msft]

Hi @DAllen365 :

Do you need to use different form controls to submit data to different data sources? If this is the case, I have two suggestions:
1. Use an app: just need to put different forms in different screens to achieve such a demand. You can create another homescreen to allow users to navigate through this screen to other different screens (using the navigate function)
2. Use multiple apps: You can navigate from one app to another through deeplink. If you are not familiar with the canvas app, I suggest you not to use this method.

Do you want to save the data to be submitted as a draft first, and then submit the data in the draft?

If so, you can save it in a collection first. Just call the data in the collection when uploading.If different data sources are involved, multiple collections can be created to save drafts.

About point 3

Sorry I didn't understand what you mean, but I think as long as you can get the 4 parameters of data source, record, field, and value, then any update is not a problem.

In addition, rather than asking for requirements, I suggest you consider asking more specific questions and provide some technical details,because they usually requires a lot of details and is very time consuming.
Best Regards,

Bof