Twin wire boat

The 14 is a hard boat to pigeon hole really, any boat say less then 10 years old is going to be harder to get round the course then an 800.  Kite loads depend entirely on the type of kite you have.  As an example on the loads and wear on a i14, i went through two pairs of those Showa builders gloves at Abersoch dinghy week in 07 (obviously i play the main as well)  Kite hoists and drops on a newer 14 take lots of fitness and technique.  Having said that once we had our boat finally set up right we were as quick as the mid fleet 9ers upwind at the ovi inlands and faster downhill then all.  When things go right with a modern 14 it is just an awesome boat, just the learning curve is expensive and tough.  I cant speak for the older boats as i never sailed one in anger (i did own a penni years ago) I would in your position buy an 800.