There is almost certainly no way that you should get a custom guitar yet. You'll know when the time is right to get one. For now, get a decent "branded" guitar. Other users here have mentioned the Ibanez vs ESP vs... points about neck styles. The only thing I would add to that is that you should get down to a guitar shop and try out as many different types of guitar as possible (in a wide range!). Make a point of saying to the staff in the shop that you're in the market for a new guitar, but that the purpose of your visit that day is to see what styles suit you and what styles don't.
I did this very recently, making the point that the purpose of this particular visit to the shop was to try out guitars to find out what I wanted (the inference very strongly was that I wasn't going to buy that day, though I didn't actually say that!).
Most shops are okay with this - if they treat you well, hopefully you'll buy from them when you're ready to get it!
The up-shot: don't drop loads of money on a guitar now! You will still be able to get a custom/expensive guitar later, and you'll appreciate it more!
Roo