Comcast & Sharp 37" LCD with 1080P

[River]

Greetings! what a great forum, glad i stumbled in.

ok, this past weekend "the boss" agreed we could buy a new tv, but one restriction, had to fit inside the big $$ armoire.

so purchased the Sharp Aquos 37" lcd, full HD 1080P, hooked up through comcast's generation II dvr, the DCT6412 model.

reading about 1080i and 1080p is one thing, but then when you start looking at all the options in the set up of the tv, and then access the menu with the comcast remote so you can change the settings in there, it is a little confusing, especially when there is not a setting for the 1080p in the comcast menu.

my settings right now for the comcast box:

tv type 16:9
YPbPr output 1080i
4:3 override stretch

i am pretty sure that the tv type is the correct ratio, and since comcast's options do not have 1080p, that 1080i is more than likely correct, correct?

but the setting that i am not sure about is the 4:3 override, which has the following options: off, stretch, 480i, and 480p.

what i've been trying to do is set one of these 4:3 override settings, then look at various channels, and try to figure out what looks best, but it's confusing when you go from a (hope this is correct?) from an analog signal with a smaller ratio (4:3?) channel to a digital channel.

then, on top of that, the tv has various viewing modes, stretch, dot by dot, smart stretch, and zoom. (i believe stretch and zoom are basicaly for dvd viewing?) and all of this makes the old gray matter start spinning.

maybe some one here smarter than me can help me out with an explanation and what would be the best for my set.

Edited: have done some more googling and from what i've read, the 4:3 override is more or less based on individual user preference, and i've gone in and checked out all the different settings for 4:3 override, and then checked to see how that effects my tv. with one setting it will fill SD programs to full screen, and put non HD programs on HD channels to side bar, with other setting full screen on all, or the user can use tv remote for viewing mode to change the picture to however you want.

right now i have mine set to 480p and that seems to give me the better picture on SD programs, but then when i change channels between the two i have to wait for the re-sync, where with the other settings this doesn't happen.

Question: now that i've done more reading, are there any programs broadcast in the 1080p format yet? some say this might not ever happen. but the format improves newer dvd movies that are in this format, right?

if i have the 1080i setting in the comcast dvr at 1080i, and my tv is 1080p, how is the redraw of the pixels being done, does the tv revert to the 1080i?

thanxz a ton !
River