If you build it yourself you'll have fun, and it will be even more educational. You'll also be getting the major benefit of having a device that you didn't order based on the word Bitcoin as all the parts came from generic sources.

The assembly isn't difficult. But to Make assembly even easier, You can buy the pins pre-soldered, where you push/hammer them in. Those Parts are listed on the seedsigner website also. Agree with shishi- Buying a fully ssembled is fine from a trusted vendor, but it is quite interesting to assemble yourself.