There's two sides to the fact that there are lots of really well made and good shooting bows available.
One side is that it is tough to go wrong as long as you buy from one of the established and well respected bowyers. Do your homework by reading as much as possible, looking at photos, talking to the bowyer, ect. I have custom recurves from several bowyers and while I have my favorites I could happily live with any of them.
On the other hand, every bow is different and with the prices most custom bows go for, to say nothing about the waiting period, I would be very cautious about ordering a new custom without spending some quality time with a similar bow first. I mean more than a few shots, I mean tuning it up and going through the process of really getting to know the bow...first impressions can change as you find the right arrow setup, brace height, and just get used to it. Ideally, the best way to go about it is to start buying and selling used customs to see what you like. It will take some time but since used bows hold their value well you won't loose much in the process, and gain a ton of knowledge. Besides, you might find the bow you love used and save a bunch of money and not have to put up with the waiting period.
I've had lots of bows over the years and I can't any of them were not well made and good shooting bows. I can say I didn't really care for all of them though; even though they were well made and nice looking they were just not my cup of tea for various reasons. I now have a couple bows I ordered custom made, another custom on the way, but they are versions of bows I have hanging on the wall that I bought used. Aside from aesthetic choices I know exactly what to expect when I open the box. I also have a few gems I found used in the classifieds that aren't going anywhere...
Another thought, I know you are looking for a longbow...have you spent any time with a nice recurve? I'm not saying one is better than the other but they are definitely different and most of us gravitate toward one or the other. I would never know that I prefer recurves if I hadn't had a couple nice longbows along the way. Just another variable to consider and another reason that the classifieds can save you a lot of money in the long run.
Good luck in your search!