The spacers Alex linked will fit, however they are 20mm spacers, so may be too wide for what you are after. Without knowing your wheel offset, we couldn't say whether they would be suitable for your new wheels.
Since you've chosen 10mm (sounds like you've already bought them), I'll assume that is the correct size you want. At this size, you should be fine to just use extended wheel studs. (Larger spacer sizes put a lot more strain on the studs and it can be considered a safety problem, but <15mm it's generally accepted to be okay. Hubcentric is always better though.)
I believe the standard studs are ~45mm, so you'll want 50mm+ M12x1.25 studs. (Can someone confirm?)
You can find a list of traders here, but the ones Keyser mentioned are your best bet. Not sure if they stock extended wheel studs, but they should be able to advise further.