Are we able to put bigger size speakers in the door and deck? If so, what is a good size to go with?

How big are you thinking? You could do 6.5s all the way around if you made some brackets to hold them.

I am not sure how big. Sometimes on cardomain I will see some door speakers that are too big, but have them locked in there securely. I was just wondering if anyone here had something like that so I could get an idea maybe

You could also build kick panels. here is an example

Hmm, do they get in your way much? Do you still have your door speakers, or do those have to be disconnected for the kick panels to work?

Yes they can get in the way because the ones im using are big box speakers, however im working on new panels and with the right use of fiberglass stuffing, you can make a smaller box sound bigger.

If you go to this thread:
http://www.bonnevilleclub.com/forum/...ic.php?t=17089
You can see where I put new tweeters in my doors, and if you look carefully, there are 6.5" drivers in the doors. I would post more detailed pics, but the images I took from the construction process were on my brother'* camera, which he hasn't been around for a while. Basically, a Dremel tool is all you need.

I've ordered another set of components to install in the rear doors as well. Will post when I get that job done, however my car is in the shop due to a collision, so this may be a while before I can tackle it.