Header recomondations for 5S-FE, Need to replace stock manifold Options

[Sandhillpam]

I'm doing a full motor rebuild of a 5S-FE for my 1997 Celica daily driver. I'm thinking about buying a set of headers for better performance, but also mainly because the stock exhaust manifold is in poor condition. I've seen several different brands available, but am not finding much information about any of them. I would like to find one that will work with the rest of the stock exhaust system on my car and not make it excessively loud. My Celica has a Catalytic converter located just below the manifold which has an O2 sensor and there is also another O2 sensor in the stock manifold.

Is there a make/model of header that will simply replace my stock manifold and allow me to use the catalytic converter and both O2 sensors?
Or, since I've noticed that other posters who have headers have not really seen an improvement in performance, even if it might cost a little more, am I better of just buying a new stock manifold?
Does the heat tape that I've seen on some sites do a good job of controlling excess heat?

This is one brand I've been looking at: https://www.amazon.com/Stainless-Headers-Ex...s=Header+Celica

[HardHead93]

I had that header on my old 5s and if I had to guess I maybe got an extra 5-8 horsepower (no dyno to prove it). It does eliminate one of the 2 cats so there will be a noise difference. In my opinion it is not worth it but in your case if the stock exhaust manifold is in bad shape it is a cheap solution.