I'll suggest getting a newly-made
operating rod spring. The linked version is stainless steel, but is wound so the spring constant matches the original military spec. The extra-power op-rod springs from Wolff have caused some folks issues.
Another item to get is that gas cylinder wrench you see at the top of the photo, above. It hangs onto the front of the gas cylinder so you can put some serious torque on the gas cylinder plug. Gas cylinder plugs loosening during firing is a constant nuisance, and that tool will let you mitigate it.
If you ever find yourself in front of a pile of gas cylinder locks and have your gun with you, pick one out that happens to have its threads timed so that it is just getting fully tight when the gas cylinder plug hole in it is aligned with the gas cylinder's threads. This limits some of the wiggling that tends to loosen a plug in the first place. It also anchors the whole gas cylinder's position on the barrel spline more firmly.
You might consider the
Garandgear.com gas cylinder plug. It is hollowed out inside (may not be allowed for as-issued matches). This lowers the peak pressure of the gas coming in through the gas port which lessens the suddenness with which the operating rod is pushed back, mitigating the tendency of large charges of slow powder to bend it. I view it as a safety extra measure in case a heavy 30-06 load somehow finds its way into the gun and is fired. You can always change it out for the original if a match requires it.
You could also look at getting one of the
vented gas plugs. These have adjustments you can make to tune them for specific loads. It's more bother during load workup but has the advantage that you can pick a degree of venting that slows the op-rod down until it is dropping your brass nearby for easier recovery.