I haven't bought any Breguet yet so I'm not sure the straps i have bought would be a good fit, but I can tell you there are some really good strap makers out there.
It depends a bit on your budget and what style you are looking for but some good ones that come to mind are:
Highest end:
-iwc uses santoni. ebay - $600 ish
-Kaufman
-Camille fournet
Super premium (Handmade)
dangerous9straps.blogspot.com
-ABP (Atelier du Bracelet Parisien) watchbands,
Combat straps montreal CANADA
Very nice handmade
**Bakeka handmade (very nice for panerai & for the money. He does calf leather only 60-70€)
**Orloff super nice a more dressy look. Try them for an allegator.
**Jacob watch straps spain (very nice. Leather for panerai 80-95€, alligator 135€)
**Martu leather straps
-Bosphorus
-Gunny straps
-Nero - on rwg john g. Looks great
Simona Di steffano italy "alchimist"
Di modell german
Corrigia