Harris Cyclery should have front and rear drum brakes. The only drawback is they add a modest amount of weight to the bike but they have two advantages - they get around the issue of brake reach and they give the bike a cleaner look.

The AW hub is serviceable and you can get a new cable for the shifter but for me personally, the new generation of IGHs offers more range and the hub is lighter and stronger than those that came with the original 3 speed bikes. Your Hercules can run on 700 C, but be aware than the largest tires than can be mounted under fenders are 32 C. There is a greater tire choice available in a 700 C wheel set than in the 27".