Q:

What kind of Magical Items can a Aegis with Master Craftsman build?

Master Craftsman
Prerequisites: 5 ranks in any Craft or Profession
skill.
Benefit: Choose one Craft or Profession skill in which you
possess at least 5 ranks. You receive a +2 bonus on your chosen Craft
or Profession skill. Ranks in your chosen skill count as your caster
level for the purposes of qualifying for the Craft Magic Arms and
Armor and Craft Wondrous Item feats. You can create magic items using
these feats, substituting your ranks in the chosen skill for your
total caster level. You must use the chosen skill for the check to
create the item. The DC to create the item still increases for any
necessary spell requirements (see the magic item creation rules in
Magic Items). You cannot use this feat to create any spell-trigger or
spell-activation item.
Normal: Only spellcasters can qualify for the Craft Magic Arms and Armor and Craft Wondrous Item feats.

So technically what can I build with an Aegis with Master Craftsman? I don't have a spell casting class in my multi class build nor manifester levels. Do I still need Craft Magic Arms and Armor and Craft Wondrous Item feats to build them? What about Forge Ring, Staff, Crystals, Djors, Psionic Wondrous Items.
And since I'm neither spell caster or power manifester can I place the mods the can be used with my Astral Suits in place of spells and powers when making magical/psionic items, weapons and or armor?

A:

With Master Craftsman as it is you can only make mundane items.
This feature doesn’t give you any ability to craft anything magical, just give you a boost to a chosen crafting skill and let you substitute the caster level requirement of Craft Magic Arms and Armour and Craft Wondrous Item and use that rank as a caster level when you craft items with those feats.
Yes, you still need to pick Craft Magic Arms and Armor and Craft Wondrous Item feats.
However their requirement changes. For example:

Craft Magic Arms and Armor
Prerequisite: Caster level 5th.
(For you with the class feature:)
Prerequisite: Rank 5 (in your chosen skill)

The feature dosen’t let you pick the Forge Ring, Staff, Crystals, Djors, Psionic Wondrous Items feats.
It only lets you pick the item creation feat it specifically mention in its text.
No you can’t use your Astral Suits mods instead of spell.
However Master Craftsman makes your rank in the chosen skill essentially your caster level when you create magical items. Because you don’t have any spells the spells in the Construction Requirement of the item will increase the DC to craft the item by 5 for every missing spell.
For example:
Making a +1 undead bane sword. First, you need to have the feat Craft Magic Arms and Armour to make a +1 sword. You also need to have a caster level (in your case ranks in the chosen skill, which if you want to do this should be Craft weapons) which is three times as high as the enchantment bonus of the weapon (CL 3 this case). To do the bane part of the crafting you need to have Craft Magic Arms and Armour, CL 3 (3 times the enchantment bonus of the special ability) and the spell Summon Monster I. As you don’t have Summon Monster I the lack of it increases the craft DC by 5 making the DC 13 (5 base + 3 form CL (as you only use the higher of the flat enchantment bonus and the enchantment bonus of the special ability; they are both 3 in this case) + 5 from the lack of the spell).

