Hey @MaLd0n
Quite a noob here, please bear with me.
I've been running (with some problems like non-working imessage, facetime, lags every now and then) hackintoshzone Sierra on a HP dc5800 sff, core2 quad q9300 cpu, 4gb ram, nvidia gt710 2Gb graphics, built-in ethernet (intel gigabit from what I gather of dpci manager info), legacy bios.
Wanted to try your High Sierra but had kernel panic first time. Now wanted to try again, following instructions to the detail.
I'm attaching the outcome of runme app, for DSDT patching.
Send me davors-iMac.lan.zip