Autolusso can supply Powerflex bushes at 10% off list price on Powerflex's website, however we only carry GTV rear bushes and anti-roll bar bushes of various sizes. We have in the past Powerflexed upper and lower wishbones on 147/156/GTs and lower wishbones on GTVs and in our opinion it doesn't really improve the handling as it makes the cars skittish over bumps and potholes mid-corner, and it makes the ride substantially worse especially on cars that already have uprated suspension, eg GTAs and Veloce models. We don't keep the upper/lower wishbone bushes in stock for these reasons but we can order them in. I'd suggest the money is better spent on GENUINE upper arms, we've seen pattern ones fail as early as 6k miles.
I've only ever fitted genuine wishbones and they all rattle within no time, all I want is a bit of peace and quiet, not worried about skittishnish really, make the drive a little bit more exciting. Still don't understand how they would harden the ride, as I said earlier they would stiffen the lateral movement but not the vertical movement of the arms.