While doing a speed test with a larger file in excess of 10MB's is a good way to get a general indication of speed, it can also provide false readings due to network congestion and various other situations.
If you're going to use a file for a speed test, test it multiple times over a 24 hour period of time and at various times of day/night.
Too many people are quick to judge speed by a single test when network congestion and your ISP may be to blame. I can easily attest to being one of those people myself, so I now run multiple tests to get my speed data. I also ask others in other countries to run their own tests. The reason? I am closer to any US data center than say, someone in Germany

, so of course my speed and PING's are going to be better.
That aside, any host with common sense would be willing to provide you with websites they host so that you can get a general idea of speed on a live website.