its hardly going to make a difference box to box and not be worth the swapping costs,
IIRC- the 1.4 16v an 1.2 16 could have the same jb1 box-ive got a 1.6 an was finding every clio up to 1.6 has the jb1 box and not the jb3 i was needing,some 1.6's even having a jb1!
do a search on here for engine/gearbox codes and you will find out what engines use the jb1,
instead of having a weaker smalller box,i would look to getting a 1.6(jb3) or look into a dci box OR stick with your gearbox give it new oil and make sure your tracking/suspension/engine mounts are all in good condition which will in turn help the life of your gearbox and ....
DONT DRIVE IT FOR ACCELERATION <as this wil help f*ck your box!
ive been threw like 3 or 4 boxes an learnt the hard way! gentle acceleration+good smooth changes+keeping on top of servicing/checks FTW!