Excellent answer. For a small bankroll cash games and SnGs are most suitable in my opinion, because a 6-8 hour time commitment is simply not worth it, if you can only afford to play for a dollar at a time. And in top of that game selection will also be to limited on most sites. So in my opinion MTTs require a starting bankroll of at least 500$.
The other factor to consider is, that the action in SnGs is more capped than in the other formats these days. So even if you get really good at SnGs, there is a limit to, how much you can move up, because games are simply not running. So if you are going to go the tournament way, you will eventually need to get into MTTs for the highest possible profit. But SnGs can be a great way to practice for that and especially for the final table, where the big prices are distributed.
So for me the main choise is between tournaments and cash games, and SnGs are really just a sub-format of tournaments. And as for which of those to choose, I completely agree, that it totally depends on personal preference. If you are not enjoying a certain game format, then you will not be able to have success, because it will quickly feel just like "another job", and for most people the hourly "salary" will not be worth it.