Building a low budget 7.1 home theater surround sound setup and had some questions?

[AM]

1) what would be a good receiver for high quality sound that is also able to be cranked pretty loud. My friend suggests that I look at the Denon 1708 and stop looking at anything else, that this is perfect for me and what I need it for. I am also looking at long term use of this so I don't want it to be obsolete in the near future. What do you think? (movies I love to crank loud are Transformers, Saving Private Ryan, The Dark Knight, and The Fast and Furious)

2) what is the best gauge for speaker wire for a home theater. is it true my friend says the bigger the wire the higher sound quality you will have?

3) just wondering if the sound you get from hdmi or a optical cable if one gives you better sound then the other?

4) is it true that all the speakers should be the same brand? right now i have no center channel and no subwoofer. all i have is 2 klh front left and right speakers 250 watts each, 2 Sony rears not sure of watts ,and 2 optimus side speakers 70-140 watts? should i buy all the same brand speakers? my friend suggests Sony. in the future i would like a whole definitive technology speaker setup!

5) i know picture and sound passes though a hdmi to hdmi cable ,but what about a hdmi to dvi cable because my TV has dvi but not hdmi?

6) and I would like a blue ray player ,but I also like to play games so I was thinking about getting a ps3. wanted to know if it is as good a a player that is only built for playing blue ray discs?

thank you to anyone that helps me. need some answers by wed Jan 21, 2009 because that is when me and my other friends are going to buy stuff (electronics)

[CLAUDED]

I will make this quick. Dennon is good, another good choice is Yamaha. All same speakers good but not absolutely needed, just get compatible. Heavier wire is better but only to a certain point. Dont waste money on name brand wire, any copper wire is good. Some higher end Blu- rays($350) are better than ps3. Sound does not pass through regular HDMI, video only. Newer version HDMI will also do sound. If you dont have the newer version, optical is best. The only advantage to HDMI audio is one less cable.

[CLAUDED]

I will make this quick. Dennon is good, another good choice is Yamaha. All same speakers good but not absolutely needed, just get compatible. Heavier wire is better but only to a certain point. Dont waste money on name brand wire, any copper wire is good. Some higher end Blu- rays($350) are better than ps3. Sound does not pass through regular HDMI, video only. Newer version HDMI will also do sound. If you dont have the newer version, optical is best. The only advantage to HDMI audio is one less cable.

[CLAUDED]

I will make this quick. Dennon is good, another good choice is Yamaha. All same speakers good but not absolutely needed, just get compatible. Heavier wire is better but only to a certain point. Dont waste money on name brand wire, any copper wire is good. Some higher end Blu- rays(0) are better than ps3. Sound does not pass through regular HDMI, video only. Newer version HDMI will also do sound. If you dont have the newer version, optical is best. The only advantage to HDMI audio is one less cable.