First I want to note that KnowShine is doing a big order of Flex PCB and it should be available in strips of 5 or 10m in a few weeks. If you are looking to do a large display, for instance icicles, I recommend you wait for those.
Otherwise… Here are the Kurt & Rod PCBs. They are 5cm pitch (20 drops per meter), 3 pin (no secondary data line) and designed to either solder the lights directly or use the RJ9 connectors. For the end to end connections you can either solder directly (mount first), or use 3-pin 2.54 pitch right angle headers (recommended) female male. If you want to use at 10cm or 15cm pitch, simply short the data and data return pads on the ones you want to skip.
Download the Gerber file and order at JLCPCB. If it is your first time using JLCPCB, you can get a coupon and almost get them almost for free, if not, it will be around $8 for 5m. When you order at JLCPCB, they sometimes fuss about the ratio on the 25cm boards and always fuss on the 50cm boards, saying that they could warp or deform during manufacture. Just tell them to proceed. I’ve ordered many of these and they’ve always been manufactured perfectly. With the rush of products from China for the holidays, Global Standard Direct (shipping) is not accepting the 50cm boards right now, so if you want cheap shipping too, you’ll either need to wait until after the holidays or go with the 25cm boards.
And if you like how much time and money I saved you, you can buy me a coffee 
Kurt & Rod 25cm
Kurt-n-Rod-25cm.zip (57.2 KB)
Kurt & Rod 50cm
Kurt-n-Rod-50cm.zip (68.3 KB)
Update: KnowShine has since adopted the same wire order as RayWu (-D+R). Essentially swapping 5v and ground, (ground being the gold wire). You can still use these PCBs with the new wire order. Rather than twisting wires around on each drop, I just swapped power inputs.