The direct leads are just that, an added length of 8 gauge wire instead of being soldered to push terminals.
The AR cone is a Kevlar type(maybe?) Carbon fiber looking cone that adds strength to the cone and an aesthetic appeal.
And the level 4 coil is just that, the level 4 coil and maybe an extra spider, I'm not sure on that don't quote me there.
They are not necessary upgrades but if you have the money then I'd say go for it. Couldn't hurt you, but if you're looking for power handling I'd step up equipment instead.
And as for the m3 8s those baskets are only available with the 8s and the higher level m3 model woofers.
If I missed anything or anything is wrong I'm going to blame it on insomnia. Regardless, I hope this was somewhat helpful. Cheers.