What existing stuff do I leave in the engine bay? 1st timer-

Ok everyone, apologies if this is 101, I've tried to cull the info from various posting but hoping there is some concise info someone can provide or point me towards.
I just got the motor out the top (yeah, next time I think I would go through the bottom now that I have an engine hoist) and I want to prep and maybe paint the engine bay and I'm perplexed whether I should gut everything or are there things I should leave? Planning on a street car, so want AC. stock brakes probably hydro boost or willwood, DBW, and I want heat to function. Thinking I will fabricate an instrument panel and ditch the porsche gauges. I will be ordering a conversion kit. Do I leave anything?
Any advice or a point in the right direction appreciated.

If you're planning to paint, then everything needs to come out.
Once you're done, for AC put back in the High pressure AC line before the motor goes in. Re install the headlight wiring. Install the ugly water tank.
If you are changing the gauge cluster to after market then you can loose all the cruise control parts as well. Save the wiring boot for the fire wall from the factory engine harness. you will reuse it on the new harness.

Thanks. I actually don't think I'm gonna paint, so scratch that prerequisite. Engine bay is fine and want to get this rolling.
Can you re-advise given that info? Ditch everything except water tank and AC and headlight stuff? Fuse box too? All the brake plumbing?
Wish i had a pic of a properly prepped engine bay-