Ok if I were to replace the valves, should I just polish the seats?
Do you have any tools in mind to do the port polish?
Replacing the
valves won't be economically viable, as you'll also need to have the valve seats recut.
Replacing the valve stem seals is always a good idea, and they are included in the head gasket set that you'll need to fit the head to the engine.
Cleaning the valves is easy; lightly chuck the end in your drill, and polish them with fine emery paper of some sort. I've a box of 240 grit DA discs that I use for this sort of thing, because I've had them so long they're no longer self-adhesive.
Clean the ports with a good flush of your favourite agressive solvent(cheap cellulose thinners for me) and some manual work with the emery paper.
It's a modern engine, so neither the valves or ports will need much cleaning.
Then you re-lap the valve seats using grinding paste and a sucker on a stick to hold and turn the valve. That won't take much work either.
Run the appropriate tap through all of the manifold bolt holes and bearing caps.
Before reassembly, thoroughly clean out all the crap and most importantly the grinding paste from the head. More solvent and a thorough jetwash is an efficient method.
I would only skim a head if it needs it; some careful checking with a decent straight edge is a good way of deciding to go any further.
You'll need a valve spring compressor with a deep throat. I have one like
this which is excellent considering the price.