2007 6.1 vs 2012 6.4

What’s better for future modding potential? I like the body of the 6.4 more but I like the interior of the 6.1 better. I have only driven a 6.1 and it was really fun but just from looking up numbers it seems the 6.4 is more powerful. But then also it seems the 6.4 is worse for future boost and can’t handle as much. 07 has 80k km 2012 has 165k km, the 2012 is like 2k cheaper.