Its not too bad cost wise. You only need parts 5&6, no need to replace the dust covers unless damaged. End of the day its up to you if you feel confident to do it yourself.
You may need a ball joint removal tool to get the old ones off >
Other than that all you need is a torque wrench to correctly torque up the bolts after you put it back on. The sets 5&6 should come with new lock nuts as they will need to be replaced.
Part 4 (steering lock) is only needed (if you haven't already got them installed) if you have wider tyres, I recently bought some of these for mine since they the car originally came with standard width wheels.
As you said get the alignment done after you've made the swap. I recommend that you try to adjust the new ones to be close length to the old.