Rookie question: when to get engine

[BA.]

I'm trying to plan ahead a little bit for when my ride gets paroled from the Body Shop. The car is 100% disassembled other than suspension.

I've put off the engine purchase for a long time because it's going to be a huge expense. I'm wondering if now is the time to get it.

Is there any reason to put the engine in place before doing all the glass, front/rear lights, bumpers, dash, A/C, body wiring harness, etc.?