There is a space in the another company 146 where the weather Radar should be that you can assign (import) the default FSx GPS to if you want it, anyone know how to put the CS weather radar in there instead?

Here are the settings for the panel,cfg in the FSX\SimObjects\Airplanes\QualityWings Avro Common\panel.RJ_HD folder.

Add these three lines at the bottom of the [Vcockpit02] entry:
gauge36=QWings146!QW146_VC_WXR_Enable, 0,0,0,0
gauge37=Captain_Sim.r001.P04!P04_radar, 442,482,395,327
gauge38=WXR!wr_display, 504,506,270,239

If you want the 2D CS WXR panel, you need to ad this to the end/bottom of the [Window Titles] section:
Window17=CS Weather Radar

And add the window itself at the end of the file:

[Window17]
size_mm=525,386
window_size=0.44
position=2
background_color=1,1,1
visible=0
ident=11223
zorder=1
gauge00=WXR!wr_display, 81,32,364,279
gauge01=Captain_Sim.r001.P04!P04_radar, 0,0,525,386

It will look like this:
http://i669.photobucket.com/albums/vv58/Markoz958/QW146%20and%20CS_WXR_zps0b21ba83.jpg

The VC Weather radar works regardless of whether the 2D WXR Panels is present or not.

I'm just wondering how to get the CS Weather Radar?  If I go to the CS site and try to buy, it tells me the charge is $0.00 and then it wants me to log in.  The log-in asks for an order #, which I don't have because nothing is shown in the basket.
Can someone give me some help on this?

Try a different browser to see if you still have the same problem.
I tested it with Firefox, and it didn't look like I would have to login to complete the order, plus it still showed the price as $14.99 in the cart.