Yes, you can use E-junkie to sell any kind of digital or tangible products or even intangible services. There's no specific setting for the latter case; just set up a product with all Digital Delivery options unchecked and Shipping / Buyer's Address unchecked (unless you need to collect a street address for purchases of that item).
E-junkie is not a payment processor, so we never handle any actual payment funds at any point. You can use E-junkie with PayPal and/or Stripe or any of the other payment services we list here:
https://www.e-junkie.com/wiki/help.payment.processors.htm
