I would say that there are two theories for buying your first Alembic. They may not apply for someone in New Zealand with a much more limited selection.
Theory one is to save your pennies and spec out exactly what you want. I am not a big fan of this since there's almost always something that you miss, or add and don't like. There are too many sales of special customs on the used market for my liking, and every one comes with a significant loss.
Theory two, the better one in my mind, is to get your hands on any Alembic to see what it is all about. Own it if you have to, or find one that you can try somewhere. In the US, it's not hard to buy a used Alembic for $2000-3000 and sell it for within a couple hundred dollars of the same price after 3-6 months. This is where being in New Zealand is going to hurt your wallet. There is very little risk.
If you're thinking about a custom order, you should start quantifying information about your preferences. Since you can spec out just about everything when you order from the factory, you should pay attention to what neck dimensions work for you. Depth and width at the nut and 24th fret should give you all the parameters that matter. Maybe also pay attention to the shape of the neck, be it like a sawed off baseball bat or something flatter.
As far as buying from someone here, I think it has a much higher success rate than eBay. Not to be a participation snob, but if you see a sale from someone who has been here for a year or more and has some posts, it's probably a pretty safe deal. I would still use some caution and read a few of the seller's posts to get a feel for the person you're dealing with, but I'd have higher expectations that the deal would go through and that the guitar would match the description.
With regard to that Distillate, I'd agree that it looks like more than a surface crack. I have seen a couple Distillates that were dropped while plugged in and had injuries like this. If someone backed out of the original deal, this could be why. The bass may function and play fine, but the value would have to be reduced by the damage. In the US, I would value the thing closer to $1500 than $2000, but it's probably still a good deal if you can get it to New Zealand with reasonable shipping charges based upon what you have said about prices there. I would want some guarantee that the bass is fully functional and that there is no flex on the top when a cable is plugged and unplugged. Maybe a picture of the control cavity as well. Some people removed or disconnected the LED for better battery life so, if it is gone, that shouldn't be a big concern.
The Distillate should be a lot closer to the sound you're looking for than any Epic. In my opinion, fretting a fretless or defretting a fretted Alembic is almost never a good idea. The side markers are in different positions for these basses and the cost of the work and chance of a screwup are greater than the cost of selling what you have to get what you want. It would have to be a very unusual bass where you couldn't find a replacement to justify a fret change operation.
