Just replaced my rear axle with a powder coated one, only used new stub axle bolts, as they were too nackered to re-use, and new brake lines.
So consider adding copper lines and flexi's to the mix. There is the brake bias valve back there too, so if your feeling flush, maybe you want to change that too. If you decide to buy new braided flexi's, you may even go all out and get some 'anti seize' mk4 calipers on there with the conversion hoses.
Some of what your replacing may be unnecessary, the old items may be perfectly serviceable, but at least you wont be caught out having everything!
What bushes you use is down to a personal choice....
If you value comfort, stick with standard genuine bushes, they will always feel better than nackered old ones, good if the car is a 'daily'. Polybushes will increase harshness. Possibly by a noticable amount, possibly not. Ive just put poly's on mine, as they were on the replacement beam I got, and my car has already begun down the poly bush route before due consideration. Ive not driven it yet, so cant comment yet....
