We don't have too many 147 owners in here who have the 105 bhp version. I have driven other remapped 147's though and I think remapping is worth the investment. Personally I wouldn't do it before the warranty period was over though.
I haven't got any experience with chiptuning this version either, but Squadra Tuning has a good name in The Netherlands and they do have a remap for the 105 bhp version.
One advice from my is....first thing how many mods are you planing to do to your car....air filter, exhaust, cams...and more...because if you have any of these in mind first do them and the...last thing you need to do is the remap "chip"...otherwise you might end up paying twice for a remap...once now before any other mods and one after you do more mods...from these 105hp you can get about 140-150hp with full exhaust system, air intake, sport cams and a remap.
As KGB says, no need to do a remap if you plan on doing further upgrades later. The Camshafts will give you a huge improvement, but only with a chiptuning specially made to suit the modification you have made to your car. Chiptuning alone doesn't give you many extra horsepowers, only improved driveability.