Todd, as you can see the subject can be confusing. To keep it simple in the long run I recomend you go with a receiver. Whatever differences there may be between a receiver and most other possibilities in the price range you are considering will be minimal or non-existant at best. The receiver will do everything in one simple package. One area that has not been discussed here is digital processing. A dvd player will do digital to analog processing but a receiver will take the digital signal from the dvd player and offer a wider range of processing of the several formats that music and sound tracks can come in. If you are going to get more into home theater you will probably be adding speakers and want to explore multichannel music. With a multi-channel receiver you will be able to do this more simply and economically than via other routes. One feature you may want to consider in a receiver is 5 channel analog input for multi channel music (SACD and DVD-Audio). Having this feature will mean if you decide to upgrade to multichannel you won't be looking for another receiver.
Because a large majority of people are buying receivers as opposed to separate processors and amps, or integrated amps, you will most likely get better bang for the buck bedcause of the economies of scale and competition in this price range.
The T742 and 1804 appear to be priced very similarly. The T743 is the current model replacing the T742 so the 742 may be discounted more to its curent pricing. As to which will suit you needs better is hard to say. Many dispute that there is really much difference in the sound of well made solid state components at this point. You will be told all sorts of things, most of which are probably not true. I think it really will come down to personal preference and specific features you like on one model or brand over another.
