It's not overly picky. Here's my cheat armor to get you started.
<armortype idname="ARMOR_NANOSUIT">
<make_difficulty>16</make_difficulty>
<make_price>2000</make_price>
<body_covering>
<head>true</head>
<conceals_face>true</conceals_face>
</body_covering>
<interrogation>
<basepower>4</basepower>
<assault_bonus>12</assault_bonus>
<drug_bonus>4</drug_bonus>
</interrogation>
<conceal_weapon_size>15</conceal_weapon_size>
<name>Nanosuit</name>
<shortname>Nanosuit</shortname>
<fencevalue>3000</fencevalue>
<professionalism>4</professionalism>
<stealth_value>10</stealth_value>
<armor>
<body>100</body>
<head>100</head>
<limbs>100</limbs>
<fireprotection>true</fireprotection>
</armor>
</armortype>
I find it comes very close to how the 'real' Crysis nanosuit behaves, despite some oddities (strength mode only works during interrogation, armor mode and cloak mode are active at the same time - which is physically impossible, and your weapons are always hidden instead of just hidden when cloaked - otherwise they'll see your Liberal Weapons of Justice). You'd have to edit the C++ to do any better or balance this thing out properly - though it could stand for some tweaking already. Might do an exoskeleton (like the Stalker one) later, as well, which will probably have a more sane balancing.
ETA: Just compared my tailoring screen to my XML file. It's first-in, first-out, and entries are dropped if they're too difficult to take on with your tailoring skill. I wasn't sure at first, but my nanosuit is the second-to-last entry in the XML, and it's that way on my fully-grinded tailoring
screen as well.
Also, this is just about the max stats you can give armor, though obviously I dialed back a few things - the suit really should be more intimidating in interrogation. Most of those are attribute bonuses. Don't go above 100 armor points; as it is I suspect I'm suffering some damage from wraparound.