>>284247If you cut the top off of most plants, 2 more will grow in its place (like a Hydra). Personally I wouldn't bother, the plant knows what it's doing.
I'd wait until the plants at least have a set of true leaves before transplanting. Your plants right now just have their cotyledons (baby leaves).
Here's my Basil and one of my Peppers. The basil is about 3 weeks old, the pepper about a month. I still have over a month before I can even think of putting them outside.