Neither, we used to use yourride. No more after an not so good experince. We are going with quciksliver this trip. I will let people know how it went after Jan 7th 2003.
(no mater who you do with I recomend a town car service with a store stop, espcailly with the young kids. It is much better then mears. One price covers everyone. Most places have vans you all will fit in, and will provide a car seat if needed. I would bring the infant one with you, since you can use it for the baby it sit in otherwise too.)
If you want to go with Happy Limo, I have not heard anything bad about them, there is also Tiffany Town Car. (mixed reports.)