I used to play a local $100 tournament every weekend for years where it was structured well and simple, starting stack of about 10k, blinds 50/100 and 30 minute levels. Play would usually last anywhere from 4-6 hours. Imo a tournament with 100BB or more to start and blinds raising at a decent interval will be enough to offer play for the time.
I also find this that might help too.
https://pokersoup.com/tool/blindStructureCalculator