Hi ya, have not fished down towards s/b, but Bourgas, which is 25 mins drive, there are many lakes,estuaries, to fish.
every one uses earth worm, carp , seems to be most pop, but have caught, trout and other fish but don't know the name in bulgarian or english.
Bought the full kit here 2 tele rods , carbon 14 foot, 2 sa/sap reels, loads of tackle, keep and landing nets etc you name it 140 leva £50.00 the lot, good little fishing shop in borge.
I Have seen some serious monsters in the lakes but cant catch them.
mind you i am not the best of fisherman, and when one has had 6 bottles of tuborg, it all goes the way of the pear, just kidding if you know what i mean.