If you want to train for bayonets, awlpike is probably the most similar, or alternatively some other 2d polearms (english bill, lances, ashwood w/o shield, long awlpike, corseque, spetum, swiss halberd, ranseur, battle fork, etc). Pike and longspear can only stab, but are my favourite polearms.
About armor, it really depends on your style. Do you want to be like in NW a relatively quick squishy target (cloth - light mails) or would you take more hits (heavy mail), or just be a tank (plate). After that, it really comes down to personal taste. Gloves give you a nice boost for your body armour at little weight cost, but are expensive. Leg armor is not that important if you are on foot (on cav it is a must), and head armour is quite important, due to head hits bonus damage.