I no longer am concerned about seeing my dick while pumped because I stay in the 4 -5 hg range. So, I am using a 2” PVC pipe for my cylinder, with a reducer glued to the end for a 1/2” tubing interface. It is just over 2” ID and works well. I had been using a 2” OD (around 1.8” ID) aquarium gravel cleaner tube which was clear. The PVC tube wall is thick and therefore comfortable against the body.
I use the vacuum pump from an auto parts store. It was the same price as the Harbor freight pump but a better quality. The pump comes with adapters which allow a connection between the smaller pump tubing and the 1/2” tubing which I use to connect to the cylinder (the larger tubing is from the gravel cleaner cylinder kit that I had previously been using).