So the rear anti roll bar is from a MK3 Ford Focus C346 which ran from I think 2012 - 2019 which can be found at a breakers, mine came from a breakers on eBay, the Ford part number for the anti roll bar is 1683278. You can buy them new but second hand they are about a third of the price. On the anti roll bar there are 2 round bits one on either end which will need to be cut off, it's pretty easy as they are not that well attached.
The drop links are from an Audi A6 C7, these can be had in either plastic or aluminium, I opted for the aluminium ones. Some come with the nuts & bolts where as others don't so try to get drop links that come with them as you'll need the nuts & bolts & it works out cheaper. If you do have to but separate bolts here the link
Then where the top of the drop links bolts through the anti roll bar you'll need an adapter/reducer as the drop links & bolt are M10 & the hole in the anti roll bar is M12, you'll need 1 each side, here's the link to the ones I purchased
Then you'll need 67mm exhaust U bolt clamps for the anti roll bar to attach it to the subframe, if you try to attach the bracket for the clamp as well there will hardly be any thread for the nut so I left the bracket off as the brackets for the bushes were good enough with a washer & thinner than the exhaust clamp bracket.
Then you'll need anti roll bar bushes, this was the trickiest part for me as there are so many suggestions but after watching an episode of Worn Out Racing on YouTube I found what I needed, the bush kit is Febi Bilstein with part number 106260 which is for a VW caddy.
Also you'll need longer bottom damper bolts as the bottom of the drop links will be next to the damper making the original one not long enough so you'll need M10 x 100mm part threaded high tensile bolts, I've noticed some people put new nuts on the end but I used the standard nuts that are on the arm, one did come off as they are only tacked in 3 places

but I managed to reuse it, here's the link for the bolts
So to sum up what you need
: Focus MK3 C346 Anti Roll Bar 1683278
: Audi A6 C7 front drop links with nuts/bolts
: M10 x 100mm part threaded bolts HT
: M12 - M10 reducer collars/washers
: 67mm exhaust clamps
: VW Caddy anti roll bar bushes with brackets. Febi 106260
: & if your doing it on the ground on axle stands time, patience & a swear jar

as it's really fiddly to do on the floor.
I think that's everything covered, all the parts I needed came from eBay.