Do some research, or look at other coins..
SKEIN, QUARK, KECCAK, QUBIT and GROESTL have GPU support. With those algo, power consumption of GPU are 30% less. And a lot colder too. And with this gpu support, of course, cpu mining is worthless.
https://bitcointalk.org/index.php?topic=475795.0It does not matter. The mining period only lasts 2-4 weeks. Scrypt is the algorithm people are most familiar with. It has the most developed mining applications.