I think most of the steel entry level 'track' bikes are going to be the same. The two you listed are similar and will be fine for your first year or two of track riding. You might be better off getting a used aluminum bike, but that is going to be less desirable as a street bike. However, finding a used bike will be easier after you spend some time at the track and get a better idea of what is out there and what you want. The steel bikes do OK as double duty street/track.

One simple thing I look at with track geometry is bottom bracket drop. Road bikes have drop around 70mm, track bikes around 55mm. Obviously if it has braze ons for brackets or water bottles, its not really a track frame.