eric1, in my mind hoops are generally round cylinders that can have a high or low diameter to height ratio and go on a base and if pressed, have a follower. Molds can be round or square or rectangular and have a bottom and if pressed have a follower. That said most people use both terms interchangeably, for example as does
Ullmers used cheese making equipment supplier in US.
Agree, a single cheese wheel from 8 USG milk would be more robust for aging than two smaller pressed wheels like I've been doing. Just meant that as an example, my problem was that next bigger size Kadova Brand Gouda shaped molds was too big for my 10 USG stockpot vat, so I bought two 7" diameter molds.
Yes 4"-4-1/2" diameter should be good for 1 USG pressed cheeses but will make a tall cylinder for 2 USG pressed cheeses, suggest going to 5-6" diameter if can.
I'd use ~75% excess height for fresh curds before pressing, 100% to be safe if you have the material. So if final pressed cheese is 4" tall, I'd make a 7-8" height mold.
On holes in side of mold, when pressing, whey needs avenues to escape. Without side holes, the whey coming out of sides of cheese during pressing will need to go into your cloth liner then down the cloth to the bottom and out the mold through the bottom holes, quite a tortuous and time consuming route. Side holes speed up the pressing by faster draining of whey and give a more evenly dehydrated cheese surface than just the bottom and top.
Stainless steel may not be historically traditional but is used in many commercial cheese making plants.
On recipes, I'd take those recipes on the website without details and pictures etc with a grain of salt (I wrote/copied them from elsewhere and thus they are not time tested). For each cheese type you want to make, I'd read as many threads as possible on that cheese to learn all the traps and tricks from others.