I want to change tire sizes on our van. How do I determine a suitable and safe size?

We have a 2005 Honda Odyssey that has P235 65R16 tires on it (OEM). A couple years ago, we had a blowout near Memphis, Tennessee (far from home) and spent most of the next couple days trying to find a tire dealer that stocked this size (rather than being on vacation). I've called some of the tire shops near my home and found that none of them stock my size on a regular basis. It's now time to replace all the tires on the van and I want to switch to a size that is much more common so if this happens again, I can quickly get a replacement. How do I determine what an appropriate, more common, size would be?I want to change tire sizes on our van. How do I determine a suitable and safe size?HI, Your nearest tire dealer will be glad to help you out with your problem . Good Luck