If you need that sort of temperature resistance, TFE or PEEK coated wire is far better than PVC, however it is normally only used for aerospace or in very hot appliances like ovens.
Materials used in ovens are normally to heavier gauge, so it is most likely your aerospace supplier.
TFE and especially PEEK insulated wire is very expensive but it sounds like cost is not an issue but appearance and perceived quality is.
Nylon 11 or 12 coated might also be available and is very tough and a lot better than PVC but also pretty scarce.
Polyester block co-polymer coated wires have also bee made. Usually marketed under the DuPont trade name of Hytrel. It is extremely tough and reasonably flexible, but unlikely realistically available retail.
To strip slippery wire like TFE coated, just wrap it around something round a few times to get a grip.
Silicone rubber coated wire is also temperature resistant (hence its use in high tension leads) but it is soft and prone to abrasion and cuts.
TFE is also fairly soft and easily squashed out or cut.
PEEK is hard and tough.
I was sarcastic as my BS meter went through the roof on the "racing" connectors comment. Second hand wire from inside the cabin area works fine if it is rated to your needs. The unique nature of your needs was not indicated or even hinted at in the OP.
I have only ever seen the complex colour coding systems used by auto OEM in auto OEM wire. I ave not seen aerospace looms, but have seen material specs as I supplied those types of materials over the years.
You will find a few real racers (not pseudo wanna be racers) here and a few OEM engineers and a few real rocket scientists for that matter. They tend not to help if they see fashion statements or BS. Keep it pragmatic, unaffected and factual and you will be swamped with useful comment. Some of the most helpful here enjoy an occasional sarcastic swipe. Most take it as a wake up call or just messing around.
Describing quality of parts as "racing" is the hallmark of a pseudo racer or wannabe and that often gets you red flagged and deleted.
A comment like I need high temperature resistance as it is xxx from the exhaust and we get yyy exhaust temperatures or I need EMI shielding or I need resistance to water or oil or whatever would get a much more positive result.
Regards
Pat
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