Hi Bryan:

The out of the box design allows you to select only one pricelist for a quotation/sales order and you can then edit the price at the line item level. A customization will be needed if you want to allow pricelists at the line item level.

EDIT:

You can activate the Discounts feature by going to Sales > Configuration > Settings, scrolling down to the Pricing section and selecting the Discounts checkbox. Odoo will add a Disc.% column to the Quotation/Sales Order Lines like so.

You can then enter the Discount % at the line item level.