Got it sorted, after a bit of fucking about with the hot glue
The only thing I couldn't find at B&Q was a double ended female adapter for a 16mm fitting - so I hot glued two bits together (see photos). Everything else is stock B&Q.
I'm converting the EF120 f&d to drip. With 6.5l pots in it there's more room to move around....and I think it will take 4 x 11l, with still more movement options than a wilma. It needs a good hosing out, so ignore the filth
It works really well when I tested it (using a 5 quid argos timer) with only the end dripper on one drip line (2l/hr). Got to wash the EF120 out tomorrow and plug in all 6 lines, but it's going to rule for 4 plants. Cheapness if you've already got a tray and/or tank.
The only non stock B&Q bit is the double ended female adapter (fnarr fnarr) that I made from two other hose screw bits (see photos) by gluing them back to back.
It's all straightforward - just don't forget the glue gun and those two screw bits...drove me a bit nuts to work it out in the end...if they only sold them life would be a shitload easier (I think they want you to buy the proper splitter head, from tap to manifold - but fuck that).
I've got an MJ500 on there atm, but if it's not enough I'll put an MJ1000 on it.
Hope this helps...will let you know how I get on...just waiting for a lone lowryder to finish and then will set it up and load it up....
EDIT: what a stoner...forgot the photos...DOH....

Have shown how the other drip heads might attach but I'm just going to go with one hose with one dripper on the end.