Hyderabad has good 3g speeds from Idea and Bsnl. Airtel giving good speeds in some of the areas only. thats what my friend's said. I personally don't know. I think same should be the situation in secunderabad.
I have been using using Huawei E173 for more than 7 months and its good and also ipad micro sim is easy to use in it. Try getting the BSNL 3G iPad microsim and their 999 unlimited plan.
My personal advice (considering that you said for downloading rather than on the go net usage) would be beam over 3G. Is beam not available in your location ?