My experience is that it is very difficult to guess what kind of teat a breastfed baby will prefer, if they will take one at all! You might assume that bottles marketed for breastfed babies are better, but babies prefer all kinds of different things.
To be frank though, if she is 8mo and has never been bottle fed, there is a high likelihood that she will never take one, so be prepared to use the sippy cup. Even then, she might not be keen, as babies who have no history of drinking EBM in a cup or bottle very often won't drink it like that--they think breastmilk is "supposed" to come out of a breast and turn their nose up at it when it is offered from any other source. Especially if mummy is sitting right there and they can smell the milk from her breasts.
Is she getting on well with food? Because if she is ready to reduce her milk intake and go longer between feeds, you may find that the problem does not really arise--a lot of babies in this situation would just refuse a bottle or cup point-blank, eat more solids and wait until you get home for a breastfeed. You could also consider stirring breastmilk into porridges and other solid foods, if you want to make sure she gets enough.
Ask your relatives about the setup that you will deal with in India and think carefully about the logistics of how you are going to pump, store and carry around milk with you, sterilize the cup/bottle and so on. Hand pumping can be slow, and electric pumps usually require a power point. I believe it will soon start to get very hot in much of India, which could affect how long milk can be left at room temperature. If you are spending much of your time in relatives' homes and air conditioned shopping malls etc. then no problem, but then if that is your situation then you will probably be able to find private places to breastfeed anyway.