As an alternative form of payment, PayPal seems like a good idea, because it will help with conversion rates. However, there are many companies who provide this kind of alternative payments service, at far better rates.
In addition, using something other than the PayPal gateway could open you up to several other convenience Payment options, like Amazon Payments, which allows customers to pay for your service using the credit card saved to their Amazon account.
I hope you will consider speaking with somebody experienced in this space before establishing your payments landscape, since this decision can exponentially increase a recurring business model's profitability.
I'm very happy to discuss offline. Our company works for Merchants and has developed a piece of FinTech for processors. We are very well connected in payments, and working with startups is one of our specialties. You can learn more on our website:
www.cnp-solutions.com. Good luck!