In general,the cooling capacity of the two will be similar at the same rpm's.
The cooling area is proportional to the area of the fans, or the square of the radius(60x60x2=7200) or (90x90=8100)
That said, I do not like either case for cooling. They have limited front intake ventilation.
I would look at the Antec illusion model which includes two 120mm intake fans.
http://www.newegg.com/Product/Product.aspx?Item=N82E16811129066
There are other good choices.
I don't like side fans, they disrupt the natural front to back and bottpm to top airflow.
If price is really critical, get the Antec 100 which is $35 after rebate, and add two yate loon 120mm intake fans for $5 each.
http://www.newegg.com/Product/Product.aspx?Item=N82E16811129098