Halfords for both, buy some cheap heavy duty fabric gloves as nitromors burns through latex and hurts!
If you plan on painting them, remember clean it all smooth with some wet and dry sandpaper used wet, always use the finest grade last, before laying on the paint.
Make sure you get some panel wipes from halfords, and clean the wheel after sanding and before painting, these degrease and pick up all the dust.
Paint in even stokes making sure not to lay it too thick, wait 10 mins or so between coats. Make sure each pass overlaps the dry edge area of the previous pass. You'll need to move your head to see this depending on the light and the colour. Silver is a bugger to see where each pass is going.
Let it dry for 24 to 48 hours and gently rough up the paint with some fine grade wet and dry (used wet) just so the lacquer can hold. Then Panel wipe it down in all the nooks and crannies like before and do the lacquer the same technique as paint.
Let it dry, at least 24 hours but ideally longer, then T-cut, polish and wax.
I've done mine recently but I had no time and the wheels needed blasting. All done on 1 hot day. The spokes show bits of crap, but the paint finish on the dodgy spoke surface and the smoother rim is quite good, just got to polish them now.
I'll do properly soon if I cant afford powdercoating.
Hope this helps anyone.
Stu