I've used Raammat 60 in my civic and its very easy to cut and aply. I only used 1 layer for the trunk and it definitely reduced the rattly and vibration from the trunk lid. This is the first type of sound deadener I've ever used so I can't comment about other brands. But I did my reasearch before buying and Raammat 60 is pretty much the same as Dynamat Xtreme without the hefty price.

As for tweeters, titanium will be brighter and silk will sound softer. It's all preference. If you want ear-piercing highs when you crank it all the way up, then titanium is the way to go. I have MB Quarts and they come wth titanium tweeters. I would suggest going to a stereo shop to listen to some components that use titanium and silk tweeters to see what you like more...

2 or 3 way 6x9's would also be fine for the rears. Some may say skip them because they are just for fill, but I say go ahead and put new ones in...

As for an amp to power your new speakers, something in the neighborhood of 75-100 watts a piece would work fine. Some examples are PPI PC4800, Phoenix Gold ZX475ti, JL 300/4....