Welcome to the mad MD's
yes you can get large heavy feeders for flowing waters & you can also get addittional clip on leads to enable you to balance them to conditions.
if your local tackle shop does not stock them ask them if they will get some in for you.
or you could give a rough idea of your area in your ?
e.g. could anyone tell where i can get hold of heavy feeders within 20 mile radius of (your area).
there normally someone who can help .