I also have an 883 and the centre of gravity is above the foot, so you don't really need a long plate for balance unless you want to tilt it for starwatching.
Mine has a 57 mm Berlebach plate fitted with 3/8" screw (advisable) but the Berlebach plates lack a cutout on the underside and would be incompatible with the safety retention pin on the GHF2W head.
All those linked by Ignatius lack an anti-rotation pin, so the only one suitable would be the Benro PL100 with lips at one end to prevent rotation.
How much is the safety of your 883 worth to you?
For a long plate compatible with the GHF2W I would suggest the following:
Clamping Plate 84mm,
Movable end stop for QPL coupling plates and tripod clamps and
Ersatzschraube 3/8" für QPL-Kupplungsplatten.
John