For sole proprietors, your PPP loan is based on your Schedule C net income, i.e., line 29 from your Schedule C.  The guidance on the PPP is very specific, loans are not allowed for 1099-MISC payments.  According to the guidance those 1099-MISC independent contractors must apply for their own PPP loan.  In other words, if it wasn't reported on a W-2, you can't get a loan for it.

I know of no special form to use for the PPP loan, most lenders will provide their own application forms.

I need to show wages for the PPP application, but I paid my employees as independent contractors and provided them a 1099

Employees get issued a W-2 and nothing else. So if you didn't issue any W-2's that means your business does not have any employees. Period.

To report and deduct what you paid your sub-contractors would be reported in the box for "contract labor".

If you don't have any W-2 employees, then you have no need for and do not qualify for the PPP loan.