I would highly recommend Pancake App (aff). I have been using it for the last couple of years to manage proposals, estimates, invoices, time sheets and support tickets for my freelance gigs, and the product has worked out fabulously for me.
Also, the lead devs Bruno Moreira and Matt Shirey are good people. They are open to suggestions, quick product improvements and even custom integrations at nominal prices.
After years of moving between different invoicing solutions, I’m really enjoying Invoice Ninja! Self hosting is a huge plus personally, as is the client area. $30/yr for white-label support is reasonable enough to me.