https://www.bhphotovideo.com/c/product/1393125-REG/intel_bx80684g5400_pentium_g5400_3_7_ghz.html
You have linked the Pentium G4560, the Pentium Gold G5400 is 200 MHz higher and 1 MB cache more than the older platform, still 2 core 4 threads but the ability to upgrade is far superior. The above list to get into the game, and then you can put in a 6 or 8 core cpu and a 1070 level card when you want more.
I had bought a G4560 at launch for a h270 HTPC build and was hoping to upgrade to 6 core, before intel released 1151 V2 socket and required 300 series. Still a nice little chip which made 6th and 7th gen I3 pointless. I have a H310 and G5400 in a DTX form (mini ITX with a 2nd slot) in a gateway sx2803 low profile case with low profile single slot 1030 gt for now.
I cannot find a 3 slot ITX chassis. x1 above x16, slot 2 and 3 for gpu, slot 1 for sound or any other single x1 card. Surely someone has wanted to put a 3 wide GPU into a Mini ITX board before. Probably just going to end up in a MATX chassis