Personally, after installing tubular arms on Big Red and my son's 69 GTO convertible I wouldn't do it again.
Both sets are off of eBay, one has the grease fittings for the lower arms on top towards the chassis making it almost impossible to grease in the future. Be aware of the fitting location. The ball joints are eighhh at best and the boots for the ball joints almost immediately start to crack and disintegrate.
I would and have used moog bushings and ball joints, purchased from RockAuto (very cheap prices) for these parts and rebuild what you have. Just, if you do go this route, make sure which lower bushings you have. Round or oval or even a mix.
I do recommend a front coil over conversion. You can adjust your ride height to wherever you like.
Just my .02