la vs magnum

so i have scrapped my original plan on using a 6.1 hemi engine due to size and crazy cost vs a small block build. i have access to the la 360 but am wondering which one is a better platform to build a 7000 rpm turbo engine with. the la engine is next to free which is a great thing but if the magnum engine handles rpm and power better i would much rather spend a little on purchasing a 5.9... opinions please thanks.