That gives you various avenues... either something thin to use as a top layer or something with built-in insulation.
Freedom of movement is going to be key, so try stuff on and see how easy it is to wave your arms around... Stretch is good from the freedom point of view but something well vut that doesn't stretch can work well too. Buffalo stuff doesn't stretch, for example, but has been popular with climbers for years.
Make sure the pockets are free of your harness, and a hood (helmet compatible) is probably good idea for those festive spindrift flurries that get down your neck.
Hard to get now mind! They've got the knifeblade pullover now, although being in powershield pro its not going to be quite the same. Or the northwall if a warm fleece liner desired.
This thing from ME seems very close to the ascenionist in principle (and might be possible to get in sales), or this (not that cheap mind.). Or say RABs fusion jacket (assuming that it'll reappear), or no doubt a huge bunch of other worthy options!
I wouldn't write anything off Its such a vague spec to go at! Don't even know if warmth possible or desirable. (when normal powershield very possible.).
Powershield pro not the same as powershield, and does go a fair bit towards waterproofing compared to an ascenionist. But its also a bit more breathable than a shell, so could appeal.
Actually Pattaguici's US website is showing a hooded simple guide jacket for this spring which is definetly another option. Shrug.
(Not quite sure if dead bird do do this right now actually - the gamma mx would be closest but does seem to be a little insulated and quite air permeable.).