you haven't mentioned your budget, but your requirements may be somewhat extreme for the typical FDM printer. The 2.5 mm pins are going to be very challenging to create if you require any strength. It's easy to snap off a 2.5 mm pin of only 3 mm tall by touching it with a finger.

I would suggest to create your models and submit them to an online 3D printing service that supports FDM, SLA and also SLS printing, and among those three methods, use as many of the different materials as you can afford. SLS printing uses fifty micron nylon powder which makes a fine granular non-layer type structure, typically very strong and well suited for mechanical parts. SLA printers use a resin which is cured with ultraviolet light. Resin parts can also be strong, but sometimes brittle.

I believe the money spent to determine the best final result will give you the confidence to purchase the appropriate printer for your purposes.

good luck