A smarty pants swingarm isn't going to improve the handling of an SV, as it stands at the moment chassis/swingarm stiffness isn't a weak spot, unsurprisingly the suspension is, particularly the front.
It would undoubtedly look very smart, but in reality, unless you wish to do something specific such as lengthen the wheelbase or radically alter the height of the bike, you'll be looking to buy a swingarm that has the same, or at least very similar, geometry to the standard one, in which case there will not be any benefit.
If you really feel your bike is lacking, spend the money on supension, for £500 you could get a nice rear shock, but doing just that highlights the (relatively) poor front end, so buy some springs and new oil there at least.
Or best of all spend £500 on petrol, get out and ride it.
