I say build it!
Every vehicle I've ever owned has been modded in one way or another, And I don't regret a single dollar spent.
If you like working on cars/turning wrenches then it's cool to sink money into it (if you can afford it), But if your going to pay someone else to do the work and you just drive the car
(pay me to build it... J/P
), Don't bother modding it, You won't enjoy the work done as much and it'll turn into a chore keeping the car running top notch.
100K miles really isn't that bad if the car has been maintained properly.
So now after reading the above,ask yourself the same question and let us know your answer.
Check Mate!