Well one thing I can say is you have great taste in tv's..
I haven't stopped smiling since putting a new 65" Hitachi Ultravision in place in my living room back last November.
Does Comcast offer any HD channels in your area? If so then that would be the cheapest route to go from what I see that most cable companies charge for the HD box and HD channels. If not then your only choice would be either Dish, Direct or VOOM.
I will say that since you have a great TV you have got to get SOMETHING for some HD viewing but be warned it's addicting. Once you see any HD programming you will find yourself hating watching anything else.
I signed up for the VOOM service in late December and am giving it a try. I have until the last of April before the "trial" period runs out and I can get a refund. Currently there is no charge for the programming but only the equipment cost. So far I am pleased with the VOOM service as well as the picture quality is outstanding. They still haven't gotten all of their HD channels in place but they are coming. I think they have 31 now with an expected total of 39.
Regarding Dish, I bought a JVC 811 from Sears and installed it myself and am using the second connection of the VOOM LNB to receive the CBS-HD feed from Dish. What I really like about Dish, unlike Direct, is that you can order just certain channels and/or packages without having to subscribe to a "base" package. So if you only wanted Dish's 4 channel HD package you could do so without having to spend money for a "base" package to start off with. If I decide to cancel VOOM I will probably pickup Dish's HD package to go along with my CBD-HD feed.
There are many choice to be made regarding who to go with and the decision is not an easy one. Direct and Dish were started up with standard programming as their main service with HD as their secondary. According to what I am reading both Dish and Direct have been promising more HD channels for months now but neither have came through as promised. VOOM on the other hand is focusing on HD as their main offering and the standard programming channels as their second.
Good luck on your choice and your new TV :up
Rick