Bones give it a go on the rod you have, after all there's plenty of fish hooked and landed on float rods over the years as long as your line strength is correct.
If you have trouble launching feeders above 3ozs then why not look at fishing the same thing but upstream. Cast up and across and keep your spool open on touch down but with your finger feathering the feeder down to the bottom, then feed a bow into your line (as big a bow as is required to leave the lead/feeder in position), keep the rod high and look for drop back bites. Usually this is a sudden knock/pull followed by the lead/feeder bimbling off down the swim with the fish attached.
A lot of the swims in the park at Ironbridge are suited to this method.