Re: Am planning to get i phone 4s 32gb
The 32Gb have nothing to do with the speed of your iPhone 4s (As highrisedrifter said).
I would also recommend of buying something newer, like an iPhone 5 or 5s. Games and Apps will most likely not play well (comparing it with the latest iPhone models), and you might experience a few lags when your internal space will start to fill over 70%-75%. I was using it for many years, but I play only "stupid" games, which do not have a lot of requirements.
If you only want to use basic apps and you want to spend as less money as possible, then iPhone 4s will be a decent purchase. Before buying it though, you must be sure to check if that iPhone is locked or blacklisted. You do not want to spend extra $60-$70 to unlock it (There is a chance not to be able to use it at all!). Hope that helped you a bit!