well you can use the KN13 springs, but b13's are stiffer and will make your ride alot better. you can use either top hats, but i would use the b13's since they will be newer.
if you want to go ca18de route, then you will have to get everything from a donor car to make the swap complete. its alot of work to change everything over. not to mention the wiring.
i have no idea about the ca16de-t you might be able to convert a ca18det intake to make something work. i dont have the info on this really.