As for gas, there are only 3 choices. First, the $20 Wallyworld Special that bakes instead of broils, don't go there, it is throw away after a year and just doesn't do a decent job! Second is the Coleman, which has the advantages outlined above, but is more cumbersome, and despite its greater BTU Rating doesn't do as good a job searing, but a good choice nonetheless. Third, and one we heavily recommend in the Webber Q, either 100 or 120. It is the best BBQ I have used. We use the one pound throw away tanks, each lasts 2 to 3 weeks, Qing 4 to 6 times a week. It is a bit heavier than the Coleman, but that is likely because the grill is thick and heavy, yet I think that is what makes it sear so well. The only thing it took getting used to was that it needs to warm up longer than a full size BBQ. As for using charcoal or open fire, it tastes so good, but is just not worth the hastle.
Ed