Anyone know where I can get one - looks like 77/83 are the only options around?

I am on 180 crank Pulley now and thats = to 75mm S/C. 180mm is just too brutal down low and runs out off puff on top quite easily + heat soak / S/C drag is worse.

80 is no longer available as I have look many times unless you go with over sea's stuff which is iffy. You are probably better off going to an 83 since they are cheaper and always available.
With the 185 you should be around 16lb's boost then I would add some timing down low if you feel you lost to much torque.

Have 76mm steel pulley from MSC used and 80mm Titanium
Lmk if still looking

Is the 80mm Fixed or clutched?

I have zero affiliation...but things I saw when I looked.

Fabtech has an 82. Runmsc.com has an 80. Both Clutched. Most 83 are actually 83.7, so you could get a tiny bit smaller with that 82, with confirming with them first that its a tru 82.

https://runmsc.com/product/msc-scp113k/

Both clutched, both from MSC

Steve , Just found that Auto Specialties will make any size pulley you need for around 600.00, they are actually making me one in 10 rib but can do 8 rib no problem.