Your support/donation is very important for the development of the project, besides, you can get more personalized technical support, advice, access the aircraft conversion file (see this list), get beta versions or modified firmware versions (if available or upon request).
Besides thin wires, you need to buy only 3 items (minimum required) - the soldering stand/holder to have your boards fixed when you solder them something like this one, a soldering iron (40-60 W), Tin (tin-lead) "solder wire" (the tin tube with rosin core 0.5 - 0.8 mm diameter) like these for example.
This is a minimal set of tools you need for soldering, if you want you may have a soldering station, different soldering irons, etc.
Try to keep the soldering time shorter - about 2 seconds, touch every joint with solder wire, then melt it quickly with fully heated soldering iron, making the melted solder leak into the joint spacing for a reliable connection. If you will keep the soldering iron tip on the joint for a long time (>3 seconds) you may overheat the joint, melt the plastic details, and shift the header pins.