FJ, a Peanut Shell is just a brand of pouch, it is not a 'type' of carrier as such.

eta: I just saw your eta, yes, you are exactly right.

You can breastfeed in a mei-tai or HAB (or any wrap for that matter), it just takes practice. Just untie the straps, lower the baby down to breast level, then retie. Once done, readjust them back up to a more comfortable carrying position. Mei-tais (and SSCs like Ergos etc) can be a little trickier to BF if you have a very long baby, and are not necessarily as comfortable to feed in as other carriers, but it is still definitely doable. I found that my bub hated being carried in a cradle position, so carriers that supported vertical positions like mei-tais were far preferable to me.

A ring sling is one of the best types of carriers for BFing, it is easily and quickly adjustable, supports a wide range of carrying positions including cradle carry, and the tail can be used to cover up with.

A pouch is also a good carrier for feeding, but does not have the advantages of adjustability.