Well 2 Channel or nali what they say are always better than sinlge one and if the size of that radiator is same like Coure than it will perform atleast 30% better than your current single channel one.
In my case i opted for 3 channel normaly this is recomended for Diesel engines but the thing is if your engine get lil weak or gaskit gets little weak the bigger radiator can handle these issues but if its a stock radiator than right away you will face heating issues.
Thats my personal experiance.
But before swaping ur current radiator its better to get it serviced and see the results. Service will be around 200 to 350 Rs and changing radiator will cost you over 3500 Rs.
About the fan speed you can get that checked by Electrition.