Assuming you're a Paladin. Assuming you spend 24x7 at melee in TF. Factoring in the penalty to melee applied to large shields, and/or the bonus applied to small shields.

What's the absolute best option you could ever get for a shield?

Would it be a medium shield? A small? A large, despite being 'less than perfect' for melee? Does the increased appraisal value outweigh the penalty?

Once that choice is made, assuming one has infinite supply and skill in a crafter, as well as infinite skill and stats in a shield-user, what is the best template and weight/etc. to achieve the 'best' shield possible (chosen template, weight, material, etc.)