It may still be possible to obtain a seed catalogue from Unwins and Kings to purchase seed but it is a bit late. They give classifications of scent, but of course scent is subjective.
Generally the White, Lavender, Pale Blue shades are the most heavily scented but there are other shades with a strong scent. Herewith a few names from Unwins
White - Royal Wedding, Valentine, Dancing Queen
Cream - Cathy, Juliet
Lavender - Romeo
Pale Blue/Blue - Old Times, Blue Danube, Rhapsody
Mauve - The Doctor
Red - Scarlett
The Old Fashioned sweet peas have smaller flowers but a very much stronger scent.