I'd recommend checking out Xero as an alternative to Freshbooks. Although Xero fully integrates with Freshbooks, it's just one less monthly payment you have to hassle with. Then you can do your accounting, invoicing and everything else you would need right there in Xero. Freshbooks was necessary before Xero added invoicing, but I just don't see the value anymore for using both SaaS apps.
Another recommendation for Stripe from me. Plus full integration with Xero.