Maybe I confused you with the brevity of my last post Soupy, sorry if that was the case.
I fitted the CBR600F4 99 calipers to VTR1000 fork lowers that I installed onto my VFR800FiX. These are a straight swap for the VFR lowers, and allow the use of the 4-pot calipers off a CBR6, as well as CBR929/954 or VTR1000 SP1/2. Had to make up adaptor plates to keep the VFR mudguard, but that was it mechanically, aside from the extraction of all the linked brake plumbing.
I don't think I would try this swap with the ST, the VTR fork lowers are quite a bit shorter than the ST so I believe you'd lose ride height and cornering clearance, and I'm not sure about the alignment of the discs and calipers, nor how fixed discs would work (the VFR/VTR discs are floating style).