It really depends.
For us, the pros and cons were very similar to those Clash listed. My girls were both put on Humira first. The biggest pro we liked was the convenience - easy to travel, shot is done in 10 seconds. The biggest con was the pain of the shot - both my girls hated it. They were old enough to understand they needed it, and so dealt with it, but they always hated it.
The other con with Humira is that it can take time to kick. For my older daughter, it took about 3 months. For my younger daughter, it took 6 months, and we had to add Methotrexate and making the shots weekly. There is just not as much flexibility with Humira - there is a kiddie dose and an adult dose. It can be every other week or weekly. That's really it.
The pros of Remicade for us were: just an IV - not painful, bloodwork was done at the infusions, lots of flexibility with the dose and the frequency (GREAT for growing kids), and that the infusions were kind of fun - my girls quite liked the chance to watch TV, relax and miss school! It also tends to kick in faster than Humira.
The con of Remicade was really the inconvenience - makes traveling hard, has to be scheduled around infusions. For the first couple infusions we did have to wait after the infusion was done to make sure there were no reactions, but I'm not sure that every infusion center does that and anyway, after the first few, they let us go home immediately.
Since you would have to travel so far for the infusions, Humira is a good option if your son is willing to deal with the painful shot. My older daughter recently moved from the Humira pen to the syringe and says it hurts less. But it still does hurt. You can use ice and try distracting him (asking questions, watching TV) during the shot, that might help.
It really depends on what your son wants - I think the thing to remember is that there really isn't a "wrong" choice here.
For what it's worth, both my girls preferred Remicade even though it was inconvenient. But Humira did work very well for them - in fact, I'd even say that it worked better than Remicade for both of them. Every kid is different though.
Good luck!!