look at it this way in terms of cost comparison. cost of a turbo 200-2,000 dependant on choice cost of a custom made manifold £3-700, cost of conrods £7-800, new pistons and rings 700-1,000 cost of an ecu 200 second hand from a twingo gt breaking, cost of a full intercooler setup 2-300, and then throw in all of the dyno time and mapping you're adding on another 1,000-1,500 easily and not to mention you will need a new transmission to put the power through the wheels faster, as the ratios in the dynamiques are much different from the transmission in the gt or clio tce that'd be 3-500 second hand.
and the chances are that you'll bend a conrod in setting up the boost pressures through trial and error, so you'll need to buy another one if they'll do a one of single con rod for you again. that's 3-5 grand straight up and not taking into account unforseen errors that may pop up.
i'm fairly confident that everyone will second me when i say the best possible option would be to buy the twingo gt engine / transmission / ecu & loom in one go from ebay. your current alternator etc will bolt directly on, this will deffinately cost you no more than 1000-1500 delivered. everything is then a direct fitment, old engine out, new engine straight in no fiddly work required exept for the loom work. then you can remap it with some of the clio 182 injectors that the guys on here are keen on, you'll see 120-130 bhp