Has anyone replaced the catalytic converter on their sedona themselves.

likey related to Oxygen sensors, the catalytic converter and possibly the fuel filters. Now I see the converters run from 60 bucks to clsoe to 700. So I think I'll be installnig that myself to avoid a huge markup from the shop. But I am having a hard time finding one online. One site had 5 pages of them with some requiring possible vehicle modification. Anyone know where to get a cheap converter that is an easy swap for the oem part?

Thanks.