First of all thank you all for your valuable feedbacks. I have again recalculated my figures based on 100 Spondoolies SP50s. This is the link to that calculation. Could you guys please have a look at this ?
Also, the place of the proposed server farm is kind of a hilly area with snow peaked mountains surrounding it. Average temperature during summers is maximum: 22C and during winters is 2c. Will it reduce my cooling costs.