Hello Ron,
here's my input:
I feel that a mahogany body gives you a very consistent even sound, while ash will give you a bit more midrange; maple should give you a bit more brightness ( and more weight often enough).
As Mica often says, on a neck though instrument, the top wood has less influence on the sound than on a set neck, but personally I can still hear the difference even on a neck-through, though it's really the neck that gives the bass most of its tone. My favorite top wood is Coco Bolo, which gives you nice sparkling highs with an enhanced low end as well; the folks at Alembic also seem to like it a lot since they call it the house wood of Alembic. It also looks amazing and that certainly does not hurt. If you want to go for something brighter, a maple top might be the thing for you (Mark King's quilted maple Alembic comes to mind); ebony should give you a pretty dark tone and walnut enhances the low end as well; I believe Stanley Clarke's most famous Alembic has a walnut top. Rosewood has also a lovely tone, warm yet fairly well balanced, I'd say; Zebrawood tends to be fairly neutral in my experience. I can't say too much about the other woods, since I have limited experience with them. More than anything though, I wouldn't stress too much on the sound property of the top, because just about any (properly set-up) Alembic I've ever played sounded great and is a dream to slap on.
In terms of the neck, I love the maple/purple heart combination which is the ideal to me. I also like the ebony/maple combo which gives you a bigger low end that you notice mainly when playing long notes; the effect is not so noticeable when you play fast runs. Ebony/maple necks, however are very expensive (1450$ option on most 4 string neck-throughs, I believe) and very heavy. For a 6 string instrument I'd go for a neck through, since it's generally more stable thatn a set neck.
In terms of Electronics, Series I & Series II are the most versatile of the lot, they come with rackmounted power supply and give you options of mono or stereo sound. They are the most expensive as well (2200$-2400$ upgrades). They also require large bodies, and I'm pretty sure that if you wanted to fit them in an Essence or Epic body, Alembic would have to use/make a larger template of that body, since they won't fit in the standard body size of those 2 models. In terms of value for the money my opinion is that Rogue electronics give you the best deal, they are very flexible & easy to use and have quick tone switches that allow you to radically change sound instantly. If you would like stereo sound without breaking a second piggy bank you might consider Anniversary electronics. At any rate, I would definitely get electronics that have the mighty Q switch and filter, rather than just treble and bass controls.
String spacing and neck width, aren't really a problem, since Alembic will customize it any way you want; you can give them your preferred settings, possibly off of a bass that you might have that's comfortable to you, or if you are unsure, they will be happy to help you figure out what works best for you.
Epic or Essence bodies are a good choice for 5& 6 string models since they are among the better balanced shapes that Alembic offers. The Epic model is generally a set neck model and having it made as a neckthrough will probably cost you more becaue it involves more work than usual.
My final advice is, if you haven't done so already, find a store in your area, and try some Alembics out, and that will give you a much better idea of your options than our comments can.
Hope this helps
Valentino
