Falci: I'm playing male V, but it's ok. I started this thread mostly because the there were so many iconic weapons and I already understood how the system regarding them worked, but wasn't really understanding the clothing side of things. Now I understand, and it's fine.
Generally speaking, I keep my V's look the same through the wardrobe system.
I think I misunderstood your initial question. I am a bit out of touch with the game as I haven't played in awhile, and I'm still on patch 1.5 so I haven't checked out the 1.6 changes for myself yet.
As a game item, clothes are treated the same as a weapon in terms up upgrading them, both in stats and rarity. And unless CDPR has changed things with the 1.6, the Legendary recipies should be unlocked at Crafting level 18, requiring the perk "Edgerunner Artisan".
Generally speaking, there are only a few iconic clothing in the game, and come to think of it, I don't know of any outside the "DLC" clothes you already have mentioned.
Regular clothing (not that iconic clothing offered anything special), even at Legendary rarity, used to be available for purchase at vendors, which is now apparently changed / nerfed.
There are still a LOT of clothing set items in the game though (still no set bonuses like in Diablo 2, sadly), spread around in secret places (and some only available after certain points in the main missions). And the 1.6 patch have supposedly introduced several new pieces of clothing set items.
Nothing special about them, but they do offer a typical look (purely aesthetic) to your character depending on the lifepath and type of build you are doing.
My personal favourites are either the Corpo set, or this list of items (white and dark green, with gold details):
Though the vendor locations (and nearest fast travel point) are probably and unfortunately no longer applicable with the 1.6 patch.
Head - Media Baseball Cap With Reactive Layer (after "I Fought The Law"-mission)
Location: Regional Airport
Alternative: Boss Mafioso Trilby With Armoured Lining
Plain Secondhand Flat Cap
Location: RNG clothing vendor
Face - Shiroi Tora Photoelectric Sport Glasses
Location: Rancho Coronnado, clothing store (Mallagra & Manzinita)
Outer Torso - Saeko's Prototype Tactical Aramid Breastplate
Location: Corpo Plaza, clothing store (Reconilliation Park)
Inner Torso - Arcticombat Semi-Formal Button-Up
Location: Wellsprings, clothing store (Cannery Plaza)
Legs - Reinforced Duolayer Techie Cargo Pants
Location: Rancho Coronado, S-curve (Tama Viewpoint)
Feet - Stylish Rock Garden Tungsten-Alloy Steel-Toes
Location: Corpo Plaza, clothing store (Reconilliation Park)
Suitable weapons:
Wilson's Pistol (quest), Skippy (quest / unique), M251 Ajax, Shingen Mark V (unique)