Going from Breakout board to custom Assembled Board

I will try to keep this as quick as possible. I see an accelerometer on adafruits website that I would like to integrated into one of my PCB designs. On eagle CAD I see when I click on the component its foot print comes with all the individual components that make the device work. My question is how or where do I buy those parts from. It seems as though adafruit only sells the devices already mounted on boards. I would just like the Bill of materials that make up that device and to buy that bill of materials from adafruit to send to a manufacturer to mount on my board.

I just want to buy what I see on the breakout board as individual device "kits" if you will. Only other way is to de-solder each component from a purchased board and placing it on the new boards in the correct locations. AKA not gonna happen.

Why not just buy the parts you need from an electronics supply house like digikey, or farnell, or newark?

In the USA, digikey is great - shipping is cheap and fast, and prices are reasonable even in small quantities.

You won't find "kits" for breakout boards that would involve soldering SMDs - the people who buy kits are afraid of SMDs. The people who aren't afraid to solder SMDs buy from electronics supply houses like digikey.

I'll be honest im afraid of everything at this point. My main issue is that with digikey how do I know if the microchip or microprocessor on digikey is the exact same one that the adafruit breakout board used?

Or should I just look for one with the same specs. I.E. -3G to 3G range analog output kinda thing.

Should I just make the components try to match up as closely as possible from what I see as the total external components from the eagle Cad file of that device.

I hope this makes sense.

Usually, most parts on the board are not critical (for example, passives like resistors and caps are almost always interchangable with others of similar ratings).

The chip itself (or sensor, or whatever the critical component is) is critical (if you don't see the same part number, refer to datasheet for information on differences between part number), but most of the supporting parts, not so much. You need to understand what the role of the parts is in order to integrate that design with your board and have a good chance of avoiding mishaps. If you aren't at the point where you can understand what purpose the parts serve, and why they chose the parts they did (having read the relevant datasheet), you may not be ready to design boards with that part yet.

Since you're not very comfortable with this stuff, have you considered (for your first boards), instead of integrating everything onto the same board, put the complicated stuff (the sensor or whatever) on the breakout board from adafruit (or from ebay, cause you can probably get a clone of the adafruit one for less on ebay), and put pin header on your board to connect to it. That way you can do the simpler parts of the circuit on your board, and get some experience designing boards, and as you get more practice, you can start integrating the trickier hardware. There is absolutely some hardware that you can get on breakout boards for a fraction of what you'd pay for the parts except in massive quantities, thanks to the miracle of chinese mass production.

Ahh the part number can most likely be found on the data sheet! HA! YES!!! I think this is the part that was eluding me this whole time. However, I have been doing something like you've just mentioned. I had a custom PCB fabricated with pin holes to mount the break out boards directly to the new board. I don't know why I didn't bother to look for the critical component part numbers in the data sheet. Guess I was a bit over whelmed. Thanks for the advice!