Taiwan currently already has the ability to build the IDF fighter planes, UH-1H, F-5s, they can build turrets for tanks (M60A3, CM32 etc) and of course APC such as the CM32. The only major problem with the advancement of the Taiwanese defence industry is that there is too little funding. The government only looks to their own defence industry when all else fails. Right now, under these circumstances I presume that they would continue funding and perhaps increase the budget of Taiwan's defence industry to develop and upgrade their military. As mentioned before Taiwan is currently going to upgrade their IDF to C/D standards.
Taiwan already mass produces ammunition, and has a substantial amount of investment in their missile R&D and production. So it should take substantially less than a decade for Taiwan to fully build up its defence industry, with the right amount of funding of course.