8 ohn / 4 ohm and speaker box question

[tazattitude]

Hey Guys,
Looking for a good setup starting with the following...
I was given 4 hole 8" speaker box that is made for my 66 c10 to replace the fuel tank.
So, I will be going with this.
I also got some brand new 8 ohm mid range 8" speakers.
So I don't hack up the dash, I want to use the 240 watt USA-630 stereo.
I also plan on getting the kick panels with the upgraded speakers (pioneer I think they come with)

A question is do I have to stick with all 8 ohm speakers?
Can I use 8" 4 ohm bass speakers in my box?

Do I put the bass speakers on the outside 2 holes or the inside 2 holes of the box?

What would be a decent amp to go with along with what speakers(suggestions please)

Thanks!