Should I wait 5-7 years for a BTO? Resale in between then? EC/Condo after 7 years?

If you can wait, go for bto.

If you can't wait, go for sbf. Otherwise, go for resale hdb.

If you can afford, then go for EC that's going to be ready soon

Like what Sheng Sheng and Justin mentioned, you can consider sales of balance. However as sales of balance is by a balloting system as well so you will need a bit of luck. Alternatively you can try open booking of flat! Usually there will be an announcement of the launch date. Open booking is similar to sales of balance but it goes by first come first serve basis. So when the clock strikes 12midnight your queue number will be allocated based on fastest fingest first.

For me I managed to get a flat during the OBF 😁

SBF can be a good option if you are not very particular in location/floor level, and indeed to upgrade after MOP. Getting SBF earlier can also maximize your grant since your earning will be a lower side compare to future.

If you are ok to love with parents then BTO is good too, or get a resales with grant first, then get your first bto in future when you got good location.

I too am in a similar situation as you. What I did was to try for sbf.

The only issue is that there are already completed units in the mix and my plan is to ROM by end 2022. So if I a high number that only has those units left I may need to forgo this round.

If you are already married or will ROM soon, this will not be an issue and you can definitely try sbf. There are usually 2 rounds every year.