CAT6 also has cable with a solid core or not... there are a lot of different kinds. Honestly unless you live in an industrial complex just get the CAT 6 non solid core if its the same as CAT5e. You don't need shielding unless its some special use case. The solid core will be better for long runs, but in a normal house you are probably hard pressed to get 100' runs and even then thats not "long".
Because I have boxes the stuff when I ran my house I have 3 going to each room, CAT5e, CAT6 and CAT6 solid core.... there is 0 difference between them.