I'm getting a custom acoustic made (birthday gift).  The lead time is kind of unknown, the guy has a pretty busy life, but for this i can be patient.

So far I've picked out the basic materials; Koa wood body, bearclaw sitka spruce top, and an ebony fretboard.  Basically i like a really bright sound.  Just wanted some thoughts on the choices so far.

Bearclaw top example;
Bearclaw
Koa guitar example (obviously the top will not be Koa, but this is a good look at the grain):
Koa

I like the woods.  But, more importantly is who is making it.

To be honest unless the luthier is someone with a track record of producing high end guitars you'd be better served buying a guitar already made.  

What is his projected lead time?  Does he do this for a living?  How many has he made and have you ever seen one?  How much is this going to cost?

If he is an unknown and charges you $2000 for wood and construction you will have a $200 guitar when he is done (resale wise).  It may sound great but no one else will buy it.

I'm not commenting on his skills because I don't know.  He may be a genius but if he is unknown understand the risks are much higher and the resale non-existent.

I must fully agree. I would love to have a Lowden but the price of entry is too much for me.
If I was to have a guitar built for me and spend lots of money it would have a known name behind it.

In my opinion the tonwoods you pick are absolutely key. This would include the bridge, bracing and kerfing, as well. Here is some information from DB - http://www.pantheonguitars.com/tonewoods.htm He, obviously, knows what he's talking about. Here is an even better link to some folks perception of acoustic tonewood properties - http://collingsforum.com/eve/forums/a/tpc/f/74760485/m/174102163

More important that wood would also be the type of instrument you choose. An OM, or 00 will sound tremendously different than a jumbo or a dread. Obviously. I have played a Maple bodied grand auditorium from James Goodall that had a Port Orford Cedar (sp?) top and it was exceptional - very bright, even though the top wood was known for its kind of mellow or dark qualities. My guess is that you want something similar to what you hear in your favorite set of players.

I purchased a handmade instrument and it is absolutely everything that I ever hoped that it would be. I hope that you find what you are looking for, as well. It is very much worth the price of admission. If you are happy with the end result it will never be replaced - even if you eventually purchase other instruments.

Good luck!

Actually Lowden is well enough known to get your investment back.  If the OP really wants advice he needs to rtell us who is the luthier and the price.

BTW, absolutely agree with comments that body size and type are also critical.  I love OM size guitars.

Lots of good comments here.  All I can add is, if this is truly custom, ask your luthier if you they can install stainless steel frets.  Although SS is supposedly very difficult to work with from a construction standpoint, if you can pay extra to have them, you'll be so so thankful ten years from now, when you don't have the typical wear grooves in the cowboy chord positions.

Thanks for the input all.  Good points all around.

 Yes, I have heard his other instruments and they sound fantastic.  His lead time is probably closer to 6 months, but that's because he's got other people in front of me having one made.  It's not his main source of income so he's gotta fit it in where possible.

To Fingerpicker, thanks for those links.  It was surprisingly difficult to find some information on tone woods that was not so general it was almost vague, those links definitely helped out.  

Thanks for all of the input, I've actually got a sit down "meeting" with the luthier himself coming up, I'll be sure to update and provide pictures when the time comes.