We've been using DT Donate for a few years now on our church website... back in Joomla 1.5 and now in 2.5. We have two different payment gateway accounts setup and our congregation can choose between them for giving online. It's great because people can even designate where the money is intended to go... tithe, building fund, missions, etc. We've also received help when needed from DTH, but this component is so easy to setup, you probably won't even need help. Thanks guys!