First, your don't need a $100 HDMI when a $15 cable from
Monoprice.com will perform perfectly. Offhand, digital TVs work best with HDMI or DVI cables while analog TVs, such as my older Mitsubishi Diamond rear-projection CRT, work best with component cables. While I was glad to spend a few extra dollars for quality component cables and speaker wire, I would have only wasted my money if I had purchased an expensive HDMI cable.
Moreover, in some cases you may not noticed a difference component and HDMI. For example, I have a Sony LCD that has a native resolution of 1386x788 and I don't notice a difference between component/HDMI on this set. You may wish to borrow a HDMI cable from a tech savvy co-worker and give it a try. If you do not notice a discernable difference then you may wish to keep the component cables in place. Since the DishHD-Lite product is already being downrezzed and bit-starved, you probably won't notice an improvement using HDMI.
Lastly, pixelation probably has more to do with a faulty receiver, bad installation/equipment, Dish Network software or bit-starved/bandwidth starved DishHD-Lite than it does a bad HDMI cable.
I highly recommend the low-cost, high-quality cables from Monoprice.com.