Are you looking for a 2x8 or 2x16 kit? I imagine a 2x16 kit, so...
Ddr4 4000 cl14 is a very binned and expensive kit, even if you can find one. Only top tier b-die can do it at 1.55V. I would recommend (in 32gb kits) if not wanting to pay for that amount, to get either:
-GSkill F4-4000C16D-32GTRSA (4000 cl15 flat @1.40V) at around $300
-GSkill F4-3600C14D-32GTESA (3600 cl14 flat @ 1.45V) at around $380
-TeamGroup TF13D432G3600HC14CDC01 (3600 cl14-15-15) at around $280
With some luck, you would do 4000cl14 bumping Voltage to 1.5 or 1.55 on those kits... I'll try the last one in a few days

Best of luck.