Recommended Tests

I hope this is the right place to post this and hopefully it finds some people who know a little about this stuff. 

I recently signed a 2 year contract with Sprint for wireless internet.  I live in rural OH and this was my best option.(I think) Cable and DSL do not have enough potential business out here to expand and I'm hoping as cell tech improves so will my connection which makes buying hardware a little more senseable.

Here is my untweaked up/down test,

:::::::::::::::::.. testmy.net test results ..:::::::::::::::::
Download Connection is:: 106 Kbps about 0.11 Mbps (tested with 512 kB)
Download Speed is:: 13 kB/s
Upload Connection is:: 84 Kbps about 0.1 Mbps (tested with 386 kB)
Upload Speed is:: 10 kB/s
Tested From:: http://testmy.net (Main)
Test Time:: 2008/06/26 - 5:10am
D-Validation Link:: http://testmy.net/stats/id-XZFIMGUP1
U-Validation Link:: http://testmy.net/stats/id-CD74AZEHO
User Agent:: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.14) Gecko/20080404 Firefox/2.0.0.14

I have since done a lot of tweeking on my computer via  * Advanced Tweaks [not for Gamers only] *  by ROM-DOS, which has improved my performance but I haven't done much on the signal end of things.

I am using a Sierrawireless Compass 597 through a Cradlepoint MB1000 router.  I have 2 machines connected to this router and both are getting similar results.  I purchased a Wilson Trucker Omni antenna which didn't seem to improve my signal, though I have not yet mounted it with any significant elevation.  With just the Compass 597 I get an 80% signal which ran about 82dB to 96dB depending on time of day. 

The tower I connect with is just under 2 miles away with no LOS, there is a waterway which crisscrosses the area between the tower and my house.  How important is line of sight with a radio signal?  I have been offered the use of an old (very old) Yagi antenna, would this work better than my omni?  There are several cell towers in the area which are owned by Norfolk Southern Railroad, would these be interfearing with my signal or do they run on a different frequency?

Would upgrading to a business account with Sprint give me a better connection?  I know it would cost more but the only bonus I can think of in the low population area that I'm in is that there would not be a lot of business traffic.

I know I will never get a connection that compares to cable/DSL but if I can fine tune this 1xRTT then maybe I can survive until EVDO can reach my house.