Speaker Help

I have a 2003 Tacoma single cab. Manual windows and 6x8 speakers in the door pockets.

I was wondering first if 6x9 will fit in the door pocket speaker mount if I use aftermarket grills? If not can I modify the mount by cutting it to fit the 6x9?

What size tweeters are in the upper door? Lets say they are just for example that the tweeters are 1". Can I put a round tweeter in that mount.

What I want to do is buy a Infinity KAPPA 6X9 component set. put the tweeters in the upper door put the 6X9 in the door pocket and put 2 10" Kicker shallow mount subs behind the seat. With the shallow box I found on eBay.

If I can't fit the 6X9 I may settle for the (5x7)6x8 JL Audio. I hear they are the best 6x8 thats less than $300 a pair.