de-cat adds alot of extra noise, but also alot of pops and torque
My 'silenced' de-cat made my exhaust around 40% louder on the motorways and under hard acceleration, if u can live with that get one for sure! As my car is used for everything I couldnt live with it, if I was single it would be fine
182 manifold is decent yes as its a 4-2-1 not just a 4-1 like the 172's, also matched inlets largely depend on how bad your current ones are, obviously if yours are awful at the moment you will see a bigger increase than others. After having my inlets off today mine arnt infact that bad compared with a few ive seen on here and other websites so im not going to bother for the time being!
188bhp seems alot for those mods tbh , maybe ill put my car on that same RR and see if i magically gain 10