I think shooting and reloading would be a great thing for you to spend your time on. considering what most 14 year olds are spending their time on nowdays.......
assuming that your parents are behind you on this....
this is what I would suggest for starting out.
a savage tactical or varmint rifle depending on your preference,toppped with a good scope
do NOT chintz on the scope! my recommendation would be Sightron S2, Nikon Monarch,or Leuopld vx3.
You could have the rifle with the scope for around 800-1000 depending....
also .308 would be a great caliber to start with.
As far as reloading this is what I would suggest.
The Lee classic cast press ($59.99) this press is an excellent press for the money! it is equivelant to or better then the RCBS rock chucker (which is $107.00)
then you will need a scale.
I would reccommend an RCBS 502 scale($57.39)
then you will need some reloading dies.
I would reccommend Lee delux rifle 3-die set ($25.99) this is available in .308
Then you will need a good reloading manual.My personal favorite is Nosler ($20.00)
also a powder dispenser would speed things up.I have used RCBSs for years and couldn't be happier ($65.00) but you could get by with a funnel and a trickler (for about $15-$20.00)
Then after a few reloads you will need a case trimmer as they grow in length and for this I would reccommend Lees case trimming system for it is simple and straight forward.
For full length sizing you will need to lub your cases. these are just some of the basics for starting and there are kits you can buy that would include most of the above.But I guess this is what I would reccommend. also get a good "how to reload book" and research,research.
also if you know someone who reloads ask him if you can come over and get some pointers and visual how to's.
you can go to www.midwayusa.com
for all of your reloading equipment.
I hope this is helpful and don't be discouraged because of your age you gotta start sometime.
reasearch and knowledge are powerful things.
As far as a custom gun I would not reccommend it for starting out but if it is something you want to pursue the Savage action is a great action to build off of ...in my opinion.
I started relaoding when I was 16 and I am still learning things today so don't try to learn it all over night.
good luck on your adventure and if you have any more questions feel free to e-mail.