What type of electronic hardware is best suited for high temperature applications?
There are various companies that have processes for higher temperature devices.  They are by their nature much simpler that CMOS in Si.  You might be bale tt buy individual transistors.

for example Microsemi has MOSFET in SiC that operate at 150 C, Diodes in SiC at 175 C.

Look also for GaN as a possible material.

MACON has GaN on SiC amplifiers that operate to 200 C (link to pdf).

TI has a whole section dedicated to HT parts (up to 210 C) here.
here is a derating curve for one part from them: