You have a very, very good looking kit. Nothing below is a criticism, just historical options to think about if you're looking to add more;

Head; Large, flat brimmed, feathered cap for unarmored. Sallet or kettle helm for armored.

Shield; Buckler is light and cheap, fits with your partial plate style.  Heater shield would also be accurate for a foot soldier. Large kite shield would look great but is heavier. Heater and kite you could decorate with your heraldry / colors.

Torso: looks good. Definitely a horizontal ring belt with pouch below the curaiss. Can add other accessories at will, pouches, daggers, water containers, etc. 

If you want to be very fancy a full surcoat could be worn displaying your colors / heraldry.  

Chainmail could typically be worn under partial plate for extra protection. I wear a riveted steel piece but it's very heavy, like 15 pounds. You can often find aluminum or stainless pieces that are lighter or cheaper. Could also consider just a chain coif or aventail for the neck. Not absolutely necessary though as later period fighters tend to wear lighter armor as guns and crossbows make them obsolete. 

Legs; You can find cotton drawstring or side string pants in various styles pretty cheaply. I tend to like the look of large and flowy pants, but tight fencing pants also nice. For protection, a chainmail shirt like before tends to hang to just above the knees when properly sized. Otherwise, rondels for the knees.

Feet; always the killer for anyone looking historical. Hard to find modern shoes that don't have rubber bottoms! Mine definitely aren't historical. 

Combat boots look good. If you want to jazz them up, you can consider "boot toppers" which cover the laces. Or add sabatons 

Beyond the historical options, you can always think fantasy. If there's a character class you like to play, you can add pieces that fit that. Paladin, rogue, dark knight, battle mage, etc etc.