I find and buy components quickly by searching the vendors that I use most. For example, I use Digi-Key, Mouser, Arrow, and a couple others in this area. I go to their site and search as described earlier, which gives me options, spec's, and costs. Click on something that fits your application. Done.
For a random example, I could go to Digi-Key, search "IGBT", which gets
this page, select suitable stuff like "Automotive" "AEC-Q101" and similar, the power I need (calculated from coil spec's, or better than you think if you don't know), select "Logic" (for 5V), THT or SMD, how many I want, etc, and see what they have that I think fits my project.
Some suppliers have better search systems, so you can find what you want and get it elsewhere if necessary, using sites such as
octopart. In any case, get important parts such as this from a trustworthy supplier.
Hope that helps.