I'm working on a SaaS app at the moment and my co-founder/developer recommended we use Stripe
for payment processing. Stripe is very developer-friendly and has a good reputation.
If you're looking for a truly all-in-one solution, Intercom.io
may also be a better choice because they include a support/ticket system. Assuming you don't need a support solution as large and complicated as Zendesk, Intercom.io
may be able to meet all your needs.
You may want to reconsider eliminating your 30-day free trial... Lincoln Murphy from Sixteen Ventures has a great series on pricing strategy for SaaS companies where he addresses free trials and a host of other pricing-related issues. I recommend reading his blog post here
and watching the free video series (click the green button that says Pricing Page Success Formula).
By the way, I stumbled across Chefmetrics not too long ago and think it's a brilliant idea! I wish you all the best with that and Bomnipotent, too.