Welcome, and nice work so far :)
For the anti roll bar - I fitted a Rover 20mm (from an MG ZS 180) unit and used the following parts, if it helps (I keep meaning to make a post about this as I struggled to find the info when I was sorting mine out). I imagine most of the parts are similar to the 16mm, according to the internet the drop links are the same, only the bushes changed to accommodate the thinner bar.
1x MGZS Anti-Roll Bar (#1 in diagram)
20mm thickness. Not available new any more.
2x MGZS Anti-Roll Bar Mounting L Brackets (#6 in diagram)
Should come with the ARB above. As above, no longer available new
8x M8x16 Bolts (#12 in diagram)
Part number FS108161
4x for mounting the arm L bracket to the car
4x for bushing holder clamp
https://www.dmgrs.co.uk/products/fs108161-bolt-flanged-m8-x-16mm-multiple-applications-all-models?_pos=1&_sid=8a59d95b9&_ss=r
2x Bolts + washers for drop links to car (#9 in diagram)
Part number RYG10035 + WC110061
https://www.dmgrs.co.uk/products/bolt-flanged-head-anti-roll-bar-link-to-lower-arm-rover-200-400r8-400-45-zs-ryg10035?_pos=1&_sid=55e521b1c&_ss=r
2x Bolts + washers for drop links to ARB (#11 in diagram)
Rover part number RYG10034
Honda part number 90162-SK3-000 BOLT, RR. STABILIZER LINK (M10X50)
https://rimmerbros.com/Item--i-RYG10034
2x ARB Drop links (#7 in diagram)
Part number RGD10001
https://www.dmgrs.co.uk/products/rover-400-45-mg-zs-rear-anti-roll-bar-link-bush-kit-rgd10001
2x ARB bush bracket (#4 in diagram)
Part number EGP1714
https://www.dmgrs.co.uk/products/mgf-tf-rover-45-mg-zs-rear-anti-roll-bar-bush-bracket-egp1714-genuine-mg?variant=43335747174563
2x Rear Anti Roll Bar Bracket Bush 20mm (#2 in diagram)
Powerflex PFR42-515-20
Superflex 0266/20K
Rover Part number RGX10017
https://www.dmgrs.co.uk/products/mg-zs-rear-anti-roll-bar-bushes-rgx10017-superflex-pair?_pos=3&_sid=9ed9f4d9a&_ss=r
1x Powerflex Rear Anti Roll Bar Link Bush Kit (#3 and #8 in diagram)
PFR25-111
Part Number RGX10003
https://www.tegiwa.com/products/powerflex-road-series-rear-anti-roll-bar-link-kit-honda-civic-ej-ek-ballade-95-05
2x ARB end metal bush collar (not included with Powerflex kit - #5 in diagram)
Part number RGX10004
https://www.dmgrs.co.uk/products/rover-200-400-600-45-zs-rear-trailing-arm-anti-roll-bar-collar-rgx10004?variant=44419224240291