Yes and if u fit the 10 mm spacer, then u would also need longer wheel bolts (10mm longer for obvious reason), look at the classified section there is a seller doing longer wheel bolts for a decent price.
OR alot of people goes for the studs and nuts conversions, but i'll got no experienece about them at all.
Spacers and stud conversion is what I'd go for. The klonk is probably the wheel hitting the track rod end!
The Abarth set up comes with a nice conversion to studs (check with Fluffy for prices) but may be a bit pricier than doing it the conventional way. (Tweeks for the spacers, these guys for studs.)
The stud thing is pretty easy: they're 12mm x 1.25. Work out the overall length of the bolts you need, get studs that overall length (they come in 10mm increments, so go bigger if you have to) and get open end wheel nuts.
Instead of the wheels being attached by bolts, you screw studs into your hubs, then use nuts to hold the wheel in place. It makes it so much easier to fit the wheel on as you are not trying to line it up and fit the bolt at the same time.
As the overall length of the wheelnuts needed, yes. Convention is that the wheelnut is measured only on the shanked portion, but you need the overall. Always go longer rather than shorter.
Hubcentrics have a little lip (rather like the hub has) which engages with the centre bore in the wheel. It's this that actually should take all the load, not the nuts or studs.
Those ones are universal ones, not as nasty as some, but in 10mm I don't think I'd trust them.