As 10 Wheels, it's not worth the cost, the Subways are nice bikes, but just to get the shifters will be over a third the cost of the orginal bike, if yours has discs, you will need new calipers, as the calipers won't work with the STI levers, the same would apply for v-brakes, drop bars, new cables, etc, the cost of your ideal will soon be more than the original cost of the bike.

For the same cost you could pick up a complete bike from the Carrera brand like this http://www.halfords.com/webapp/wcs/s...egoryId_165710