
In upscaling, you really do get what you pay for; cheap processors will deliver a performance that - in many ways - is inferior to the unsullied DVD output. As you go up the price ladder, so the picture begins to live up to the hype.
You have a very good TV set, why skimp on the DVD player? The difference between the 1730, 1930 and the 2930 will be clearly noticeable, especially in upscaled mode, on your set. So go for the best one... it will be a few years yet before HD DVD has anything like the catalogue of DVD.