Bandwidth and latency are largely separate issues. Which of these you need to improve, if any, really depends on what you're doing.
If your bandwidth is maxing out, you may need more bandwidth, in which case it's easy to upgrade if your provider has it on offer, which it sounds like they do.
Latency, you can't do much about, except possibly switch providers or colocate a server closer to where you trade.
I doubt that either of these will make much difference if you're a point-and-click trader, although I admit I have no idea how much bandwidth point-and-click platforms use these days, as they may be very inefficient. In that case, customer support for your trading platform might be the appropriate place to ask your question.