I'd say, go for Option B. Most people pay no mind to benchmark tests because they don't always correspond to Dolphin's performance. It's not always about clock speed; CPU architecture matters a lot. Intel's Sandy Bridge chips run faster than similar ones from AMD clock-for-clock. Keep in mind too, Dolphin is also a dual-core application, triple-core if you count using LLE on Thread, so throwing more cores into the equation won't help as much as you might expect.
The i3 2100 or i3 2120 will play a vast majority of GC/Wii games with no problem. It's just that several demanding games are out of the question for full-speed gameplay, like the Super Mario Galaxy games. Most people need heavily overclocked systems to get those kind of results. The games on your list will do very well on Option B; the Hyrule Field in Twilight Princess will probably slow down as it's a large open area. Not only is Option B cheaper, but if your motherboard should be set to upgrade to Ivy Bridge chips later on, which will be even faster than current Sandy Bridge chips.
The i3 2100 or i3 2120 will play a vast majority of GC/Wii games with no problem. It's just that several demanding games are out of the question for full-speed gameplay, like the Super Mario Galaxy games. Most people need heavily overclocked systems to get those kind of results. The games on your list will do very well on Option B; the Hyrule Field in Twilight Princess will probably slow down as it's a large open area. Not only is Option B cheaper, but if your motherboard should be set to upgrade to Ivy Bridge chips later on, which will be even faster than current Sandy Bridge chips.