Last Minute trip preparation

I will leave on my big trip this summer in four days. Yet, I am still confused on what to take and not what to take with me. I am currently trying to keep my packing list to the bare minimum. Thus, I have decided only to bring the following 

1. Two pairs of pants ( 1 pair of jeans and 1 pair of chinos)

2. Two pairs of shorts 

3. Three T-shirts

4. Three pairs of shoes (One pair of running, one pair of boat shoes and flip-flops)

5. One weeks worth of underwear and socks

6. ipad mini, iphone, camera 

7. medication for malaria, bug spray and sunscreen. 

I dont think I will wear many of my clothes while I am in India. My plan is to buy local clothes once I arrive so I can fit in better. Moreover, this year I do not plan on buying many souvenirs for my students. The reason being that when I travel between Shanghai and Hong Kong, I am only allowed to bring 15Kg with me.... 

Although, I know what I want to take with me on my trip, I am not sure what to pack everything into. My two choices are a suitcase and a backpack. I know the suitcase is big and it might be hard to push around cities such as Delhi and Hong Kong. But, I will have a  lot of room to bring things back with me from my travels. As for the backpack, it is very light and it is easy to carry around town. But, the downside being that I cannot bring back any goods from my trip  and if I do check the backpack in things might get damaged or broken. 

I will keep everyone updated on my trip and let you know which type of luggage I choose.