Noooooo .. don't nip them off otherwise that is as tall as they will grow !
The flowers at 8 inches tall sound as though you have delayed putting them into larger pots or into the ground.
At this stage mine were planted in the poly tunnel 2 weeks ago, they were 12" tall. All the lower leaves were removed and when the plant went in the ground, it stood 4" clear of the soil, no more.
Make your hole and fill it with water. Leave it to drain and then pop the tomato plant in, pressing the soil around the stem, firmly pressing it down down.
Do not water the plant again for a good few days, wait until it wilts. In this time the roots will have gone out searching for water. This makes for a much stronger plant.
So having 8" submerged will give me more roots.
Do not be scared of removing all the lower leaves.
Two weeks on mine now stand about 15"- 20" tall.
All this heat is making them race away and today I have had to start supporting them with canes !
Remember what I told you last year .. Dont over water !
Give them the same amount each day, preferably twice a day.