It would be the 2MB manual test at testmy.net for upload speeds.
Whatever the tech asked you to do is the right one. The 2MB size for the residential accounts is asked for just so that the test lasts long enough. Sometimes people will run the automatic test, which really doesn't run long enough to get a good average, so they ask the residential account holders to run a 2MB test. Longer is fine, and a business account may be totally different than a residential account when it comes to testing.
As for wireless vs hardwired. Wireless may be slower, but with a good router and setup, it should be a nearly imperceivable difference for our purposes. As for hardwired being better...no doubt. A hardwired connection, when available, is always superior to a wireless connection, because routers can add problems into the mix. Not always, and not normally, but they can.