Your client will need:

3 years of financial statements
3 years of corporate returns
Well put together personal financial statement
Well put together resume & executive summary
Bank statements (3-4 months)
Projections (3 years)
If the owner holds any real estate personally with equity, he needs to understand that depending on the bank they will first take a second position on the property they own personally and SBA will guarantee the remaining portion up to 75-90% of the loan.

If you are brokering the deal, i think the max you can charge as an intermediary is 3% as per SBA standards (you may want to confirm the exact percentage).

Happy to help.