Im 32, already really heavy but lossing weight. I had a 42 pounds bullit, incredible bike but the bike was more dh-fr that I wanted (im agressive but not hardcore). The simplicity of the travel and the burliness is a plus .
Now I have a 36 pounds nomad im I cannot be more happy with this bike.
I dont know about the scream frame weight but maybe will be very close to the bikes you choosed. The scream components also would be srtong and heavy so maybe your bullit or nicolai or the spec will be as heavy as the scream.
To me, if you want a not so heavy mini dh bike my chose will be:
1) Nomad RFR kit with coil rear and a totem or 66 as a fork (38 pounds)
Nomad have a really nice feeling coming down and a very eficient pedal stroke specially on technical climbs (165 mm plushy rear travel).
2) Light weight Bullit, if you want the simplicity and no maintainance spp (I think you like because the heckler you have and the bullit you have on mind) the X9 AM kit with coil rear , boxxer team, but maybe you will be changing rims soon...and keep the weight at 35+/-
both choices would be around $4000
But remember am a SC customer.