Diawa TDSS.Its thin, has great bite detection and very flexible even though its rated 4-8oz.Small rings but it's only available with coasters. Its 80 quid from some places and has a nice fish playing .
Have a look at the rods made by Shakespeare Steve, they do a good range, some have very thin blanks and really sensitive tips, but crucially for your lad I think they will be light enough for him to cast, and not to stiff so he will be able to cast himself without much effort.
There is a good range for under ?60 (cheaper through mail order).
Tip Tornadoe Lite Cast between 3 and 5oz. I use this a lot due to having Rumatoid Arthritis in my hands. If this is still a bit heavy check out the Ultra Lite 2-4oz.
the superior is what ive got(1 multi, 1 f/s) never had any problems at all, my wife casts them and my 9yr old has had a go at casting them, my 5yr old has reeled them in on his own.
just weighed them, 1&3/4lb, not sure if thats heavier then other rods?
Got my son a shakespeare Odessa,from my local tackle shop for ?40.you can pick them up at sportsmail(cardiff) company for about the same price.I have borrowed it a few times to fish at night(i use a multiplier) and found it pleasure to use, should have stuck with a fixed spool, didn't want to give it him back.