Exhaust wrap versus coating

Hello,

My exhaust headers are wrapped in order to help reduce the heat in the
engine compartment, but I have had 2 peoples telling me that my header
will not last with that wrapping in place and that I should get the
thing ceramic coated instead.

I wanted to get the list opinion on these 2 options, is it really true
that my header will be dead in 1 year, is the coating worth the expense
(I was told that it would also increase HP)...

Also, I was planning on a 1.75" exhaust system, is that good or should I
go for 2"?

Regards, cyrille