Lots of options out there. Stay away from IBill (now scamming as eTelegate or whatever).
I've been with B-H-E for 8 or so years now. Always been good.
http://b-h-e.com/
I have some sites with Verotel as well, been with them going on a year now. They also are excellent. ACH's always on time, and target. E-mail support's a bit slow, so either call them, or use Live Chat.
http://www.verotel.com/index-en.html
You can always start with Ticketclub, but I would recommend the Plus.
