Tranasction handler for site

hello all,

first post here at devshed forums. i am working to build a site that accepts donations. however the client does not want to use paypal, they'd like for the process to feel more custom, that is they don't want the user to be directed to another site. what services do you suggest?

i was thinking authorize.net, but from what i understand this is mainly for online buying/selling. please let me know what you guys think, thanks.