Thsi stuff is always top notch. Can get it at any bike shop. However any patch that has feathered edges will do. Don't use the "big sheet of rubber cut your own", they don't work well.
More important than having a patch kit is knowing how to use it. My long time bicycle riding buddy who is a bike mechanic can not patch a tube to save his life. Other than following the basic instructions there are two key points.
-marking the hole well. Once defalted and loaded with goop you can not locate the hole easily and will off center or miss your patch.
-allow the rubber cement to dry before you apply the patch. You are not glueing but vulcanizing.
IMO a properly patched tube is jsut as strong as a new one.
If you rip a valve stem, there is no way to patch it.