We use MTrex. It was created by some people who worked on Autorize.Net. I've met with the CTO and he seems to know what hes doing. It has most of the same feat

We use MTrex. It was created by some people who worked on Autorize.Net. I've met with the CTO and he seems to know what hes doing. It has most of the same features, and I have enjoyed their tech support. They have a nice api and their website is easy to use also. I have used authorize.net in the passed and this has been a little bit easier to use.