Yes mate thats the idea...
Obviously the colder the air going into the engine the better the combustion....
...because there is a lot less heat transfer to the inlet manifold / throttle body from the head because there is a heat resistant barrier it means intake temps are less.
The inlet manifold gasket gives the biggest difference with the throttle body gasket just being seen as a may as well addition though will give some difference as again is another heat barrier - the colder the air at the very entry point the better. The gaskets are reuseable and as the OE throttle body gasket from Renault is £4.50ish anyway and isn't reuseable it is a lot better - if any its an investment lol.
Hondata are famous for making just throttle body gaskets for the civic type-rs so must be worth doing as this is one of the first mods done by everyone on the CTR (civic) forum.
The t.body gasket is a very easy mod to do as well - I'd estimate if you know what you are doing 5-10mins to change. For your first time up to half hour!
Tbh the manifold one isn't a massive task - easily done in half a day can just be a bit fiddily, esp if its your first time - like most things
I'd personally recommend using these alongside a cold air feed (if you haven't got one already). Together should give a significant difference in performance and will help with heat soak - as you know valver bays can get very warm!
Also they look cleaner :D