As a prepper it's likely your welding projects will be the backyard type. You don't need many big expensive tools. This is what I recommend that should cover your general projects. YMMV depending on what you plan for projects. You can pick up everything below right at Home Depot.
If your projects are going to include cutting metal of any real substance, especially with angles, the chop saw will save you a lot of time and aggravation. Trying to cut angles through a piece of material with a saws all is extremely difficult. With practice you can do it with a torch, but then you have to grind it down. The chop saw makes a nice clean cut
The cut welder kit doesn't include the gas tanks, you'll have to find a supplier for those. I use propane and oxygen. For thicker metal like 1" or more, I use acetylene and oxygen. Acetylene is $65 for a tank and propane I can refill locally and use a 20lb or 100lb tank and it's a lot cheaper. A "251" oxygen tank, which is a fairly good size is $35. They do have smaller tanks, but for the cost-volume ratio, the bigger tank works better for me. There is much more volume for the buck. The small tanks that you can pick up and carry will probably get you out of a mess and are handy if you need to go somewhere and do a quick job, but there isn't much oxygen in those little tanks and they're expensive
All materials at this site not otherwise credited are Copyright © 1996 - 2013 Trip Williams. All rights reserved. May be reproduced for personal use only. Use of any material contained herein is subject to stated terms or written permission.