Like the 650, with the new 1000 we went for the Givi Alloy Monokey Top Box plate (Part# SRA3105).
Givi also make a nylon version Monokey plate, but wanted a plate that was more specific to the shape of the bike, and the OEM rack. Plus the alloy version is silver, again looking like it is standard on the bike. Wanted a plate that still looked good on the bike even when not using a top box.
To mount this plate was easy, although there is more involved than simply just bolting it onto the stock plate. Givi has obviously done some good r&d, and must have come to the conclusion that the stock OEM rack was not strong enough to support a fully laden top box. After all, their new alloy Trekker Outback box goes up to a massive 58 litres.
To solve this, Givi have included additional support arms and a brace, to reinforce the strength at the rear of the rack/plate. These use the rear pannier mounts. They are a nice black crinkle paint finish.
With Givi Trekker Outback 42 Litre case fitted: