There is no real need to test on all those device. The browser is the same, for example, in the 7210, 7230, 7280 and 7290. The differences in those models are the GSM frequency.
It will be important to test on devices running the v3.x and v4.0 of the handheld code.
Regarding the models, I'm a bit confused. Many of the "models" you mention are not BlackBerry models. For example, there are no 6200, 6700, 7700, etc. models.
Here's a list of current models:
http://www.blackberry.com/products/h...ds/index.shtml
To use the browser, make sure you launch the MDS simulator before the device simulator.
-- Aric