Suspension Help/101

[gdink1970KS]

Hey guys here is the problem....
I am currently working on my 1970 chevy truck i am wanting to do a street/strip truck. I was wanting a setup that could be lowered (Preferably airbags) and still hook up on the track.. i have seen many people running trailing arms with a small notch and coil overs/bags i was wondering when this is done does the entire bed have to be notched to clear for the coils and the notch, I was wanting to tubb it for larger tires but the entire bed.... not so much

Also i have seen a number of different 4-link setups most of them a KP style where they mount to the outside of the frame rail i was wondering if this made it so they had to run a smaller tire and if so if the 4-link could be moved inside the frame rails....

I have looked at so many and they all look good i just don't know......