Our CVH engines are some of the easiest (imho and countless others) to work on. The head is not at all hard to take off, but once you take the head off it is debated that it slightly warps the alluminum, so it's good to go ahead and get a slight leveling done at a machine shop for ~20-30 or so. If you do decide on taking apart your engine yeah it would be really benefitual if you rework it all as well as hone job and rings.. it's much easier work to take the engine out than to have to work with it in the car if you're reworking it all, up to you, would be great if you had an engine stand. Very simple work, make sure you read up on it tho, it's really not that bad but don't get in over your head, have a strategy, grab one from the countless guys here that have done really exceptional work with the cvh.

Possibly the headgasket sounds to be letting an oilpassage get into one or more of the cyl's... but you could also have ring problems.. hard to tell.. any coolant passage issues you think? (check under your oil cap, if it's whitish oil look then you have water in your oil thus went past your piston rings from the combustion chamber, which was from the headgasket leaking a coolant passage and evap'ed up there)

gl to you man
-brad