Welcome to the site !!
It all depends on what the prior owner actually did or had done as far as "head inspected" and "full Service" goes , as that leaves a lot of guesswork as to what was actually checked , or replaced , or even inspected , if a cam is noisy , it would most likely mean the valves are too loose , which would mean they need adjusting to the correct OEM specs , if they just "looked things over" then i would guess nothing was replaced in the valvetrain , which would include the Timing Chain , which is what i would suspect is the "noise" your hearing , as usually when the chain gets worn it stretches and will slap around , on a aluminum head and cylinder it will echo and actually be quite loud , so what your most likely hearing is a timing chain that needs replacement , not a "aftermarket" cam noise , as it does not matter who makes the cam , weather its aftermarket or OEM , they are all adjusted to the same spec , so regardless of the brand of cam , it should not be "noisy"
Not sure with your limited mechanical capabilities , that you would be willing to take on a timing chain replacement or have a shop do it ... you can do it if you buy a Factory Honda Service Manual and follow the steps exactly , unless you do not trust your mechanical capabilities and do not want to buy a flywheel puller , as that is really the only "specialty" tool you would need to replace the chain , if you run into any issues , someone here can usually help you thru it