I have put together a kit of 3rd party parts grip EN EL 18 battery BL5 MH 26 charger to give you 9 fps for £180. ( make an offer special for NG )These have sold well to Portugul /france/germany but not for some reason in the UK . If anyone is interested its item no xxx
Saves a lot of messing about particularly as getting the right battery and grip is critical if its to do 9 fps.
I have the charger that's included in your kit, included in the package are adapters allowing you to charge even EN-EL4 batteries (and also Canon batteries, maybe not too interesting for a Nikonian...). So with a single charger you can charge the D-300/D300s/D700/D2H/D2X/D2Hs/D2Xs/D3/D3s/D3x/D4/D4s/D5 batteries, either EN-EL4, EN-EL4A or EN-EL18/EN-EL18a.
Naturally for D300x and D700 I'm speaking about the batteries that go into the MB-D10 grip.
Besides, with the (included) BL-5 adapter, the EN-EL18 batteries are interchangeable with the D500 grip (and also the D810 grip), so if you have one or both of these models, you're in for even bigger savings.
As a conclusion, a very good choice if you start buying your battery upgrades from scratch.
Ciao from Massimo