focusing lens for sls 3d printer

I am very new to optics and lasers. I understand some of the concepts involved with focusing a laser diode, but it is very general and a very small amount. I am currently building a 3d sls printer and I want to have my laser source about 8 inches (200 mm) away from the powder that is going to be sintered using the laser.

I plan to couple the laser diode to a fiber optic and I understand I will need a lens to focus the laser into the fiber optic and a lens after the fiber optic to focus the beam again. I currently do not know what kind of laser diode I will use but I need a focused laser spot of 0.1 mm.

I am currently looking at using a collimating lens and a focus lens to get the laser spot correct because from the information i gathered the ratio of the two lens multiplied by the diameter of the fiber optic will give me my laser spot diameter.

Is it possible to have my laser source 8 inches (200 mm) away and still get a laser spot of 0.1 mm?

I have looked at lens focal lengths and it seems hard to find them in the correct ratio to get that small of a laser spot at that far of a distance. I also do not want to have a big focusing head because it will be moving around a lot.

Also, I have seen focusing lens with a 200 mm focal length could I just use that after the fiber optic and get the same laser spot?

If there are any tips or suggestions or any info you could provide that could lead me in the right direction I would greatly appreciate it.

Thank you.