I like the Canfields for their purpose and price.
I am gong to suggest to not home brew them anymore than you have unless you fully understand what is needed. Bowl work and the relation of valve seat angles and throat shaping can be critical at making the head work to make power. Doing mods to either slow or to speed airflow in each section of the port can be very critical to make the port work. Most heads have port runner areas where they are too turbulent and other areas where air speed is too slow. The key with a cylinder head person whom is experienced and has learned the art or skill is where the runner needs to be faster and where it needs to be slower.
I know of two guys that are very experienced and will do you good work for an affordable fee of helping to make the heads be more compatable with your engine and what you use it for. PM me. You will have to phone or email or both to them. I have some understanding of what some engines need as far as porting so I do some porting in lower horse engines. When doing higher horse engines the heads go to professionals and depending on the budget also depened on where they go. The best or better cylinder head guys are not cheap. They are really good and have the latest equipment. The two I am speaking of do not have the latest in equipment but have tons of experience so I put those in my opinions as below for exampe RfD Curtis Bogggs. Now days he is one of the best
The intake port surface benefits none from a polishing and it could at times make it worse and not better.Usually a lightly sanded finish works pretty good. Even the CNC finish works pretty good if port has correct shape.
Never port match exhaust port to a header unless the port is needing to be made larger and you can use an exhaust gasket for an idea of not opening too much. Port matching exhaust to header is just another magazine myth. If you have a small headeder it may help but if you have a big header primary you can ruin a head by opening it too much. The exhuast needs to be opened and ported for what works, not for what your header is.
Ed