I assume hamerite paint should do the job.
If you're about to do this, don't forget the hub area of the discs, they're all too often left and are usually dirty / rusty etc and take away from the overall look
Hammerite smooth silver for the hubs works well, it's what I use and have done for years with no issues, just a great smooth silver stock looking finish
Re cleaning / sand blasting calipers etc.
Unless they're in extremely bad shape sand blasting won't be necessary. Get them cleaned thoroughly and use of a good wire brush all round, finished with a paint brush to remove any loose debris will be more than sufficient.
Unsure what colour you're considering for the calipers?
Mines came with black originally and I re did them myself using Hammerite smooth black and had excellent results
When I decided to go for red I opted for Ferrari red and bought a small tin of gloss from Ebay giving the results you see using a brush
Longevity is good if cleaned regularly and looked after, I personally though like to freshen mine up once a year in spring and have it down to a fine art, around a little over 3 hours to do all four corners.