alternative to soba noodles?
Soba is a hard to replace but if you are in a pinch you can open up some ramen and throw away the packet.
Don't throw away the spice packet! Save it for "another use". Other alternatives, depending on what you are planning to make are udon, mee krob, or hell even angel hair or fideo. FYI, soba are made with buckwheat flour. You will want a very thin noodle.
In a pinch, you could even use fettuccine. Not the same ingredients or ethnicity, but you could get away with it.
Soba noodles are fairly easy to find. Many chain groceries carry them and most any oriental market will have several brands.
I think the closest substitute would be whole wheat thin spaghetti