Ask HN: Payment processor for non-profit donations?

I have a client who needs to accept donations for his ensemble, and I'm wondering who HN recommends for payment processors.

He wants to accept one-time donations, but also recurring (monthly and/or annually). For recurring donations, there are multiple donation levels (e.g. "Donor" would be $5-24/month, "Benefactor" would be $25-$49/month, etc.) and descriptions of donor rewards for each level.

What processors can handle these criteria?

1. Hosted on the processor site (client does not want to manage databases, card numbers, etc.)

2. Can host a donation page that has multiple subscription levels as described above? If subscriptions must be fixed ($5/mo rather than $5-24/mo), that's acceptable.

3. That a donor has an account with the processor is okay, but not required.

Ideas? Thanks!