regarding the riser, yes Ubit is a good brand (im also using that), however its better if you could get the latest model (VER 009S: Version 009S). Here is the one I bought : https://www.amazon.com/dp/B08X4BGKJP

Regarding PSUs, if you are planning to build a rig, its better if you can get a server PSU (from reputed sellers like parallelminer)

Ubit 6 Pack PCI-E Riser Express... https://www.amazon.com/dp/B08X4BGKJP?ref=ppx_pop_mob_ap_share

I use molex to power the pcie riser

Could you share a link to what you get? I've been getting Ubit 6 packs for about $50. I like these because they give you options to power via 6 pin pcie or Molex. I've preferred 2 risers per Molex string which leaves room for my pcie strings to be dedicated to gpu https://www.amazon.com/Ubit-Dual-6pin-Graphics-Extension-Ethereum/dp/B08X4BGKJP?pd_rd_w=yYoBI&pf_rd_p=ec24c188-b45f-4923-921c-81937c625aeb&pf_rd_r=75BS53ZV8DA23YWYCA33&pd_rd_r=94e58ece-d137-4790-867b-ed30db517a80&pd_rd_wg=6kPFS&pd_rd_i=B08X4BGKJP&psc=1&ref_=pd_bap_m_rp_1_sc

what clips do you speak of in the 009s?

the adapter set has: 16x gpu adapter, sata cable, usb cable, 1x motherboard card.

i see no clip in the package for the 1x motherboard card.

You must use "risers". The risers are so you can install the gpu anywhere u want, instead of plugging it straight onto the board. Basically it's just a pcie extension which allows more room/freedom

You can also try pcie splitters, but I dont know about them. They split your 1 existing pcie slot into 4 slots, so you can use 4 gpus. You then plug the risers to the 4 slots.

Splitter: https://www.amazon.com/dp/B092R64W2V/ref=cm_sw_r_awdo_D760PJB8K2RHM2X3ESJX

Risers: https://www.amazon.com/dp/B08X4BGKJP/ref=cm_sw_r_awdo_H4NG6QZC6GZD4VC02KCD