HGH is huge in Hollywood. Steroids I kind of doubt in most cases. Most people lump the two together incorrectly. HGH is administered by a doctor only, and only with perscription. Perscription are easy to get, and are essentially justified as a business expense in Hollywood. It's used to treat people who feel overworked, overtired, or people who are getting older and, in this case, need to continue looking and feeling young.
The reason there is such a misunderstanding about it is due to the expense. The actual HGH runs anywhere from $400-$800 dollars per week, and the appointments to have it administered generally come with consulting fees that can make the fee for it over $20,000 a month. It's something you
can get cheaply, but without medical supervision it can carry a wide variety of risks. So you either have to smuggle it and be an expert, or be very extremely rich. Either helps.
That said, I'd want Brandon Routh again. I'd even wager Goyer would be willing to cast him. However, should studio politics or the displeasure with SR remove him as an option, I'd go with Armie Hammer.
Armie, of course with HGH, could easily get to size. His height is already more than adaquate, and his speaking voice is actually quite deep. He's got a little old Hollywood flare to him which makes him an ideal Clark Kent. To me Clark Kent should be a somewhat antiquated figure since, being an alien, he bases his CK identity on how he thinks humans
should be which would probably be an iteration of the idealic people he saw on television, and his "parents".