JMOSER:
Good choice of bike! Hand guards are well worth it. Some prefer the Touratech after-market versions but they're fiddlier to fit. You'll have more problems with buffeting coming from the screen rather than the handguards.
Do not bother with BMW engine bars, but you do definitely need some sort of protection. The BMW bars are the least effective, look ugly (IMHO) and have to be removed for servicing. The best AM bars are made by Hepco & Becker. Without bars, any small tumble will damage the cylinder heads. The black plastic protectors do a job of sorts but will not stop the heads being cracked or even holed.
Few people get the BMW rear box as well as panniers. The panniers can be keyed to the ignition key and therefore only require one key all round. The top-box is an old design off the K-series bikes and has a separate lock, easily forced, and rather clumsily designed. Most people in the UK go for a Givi box in combination with BMW panniers. Alternatively, go for a Touratech or Zega aluminium system instead.
If you have the chance to order any other accessories now, get the heated grips and any extra electric socket. The standard bike benefits from extra lights, a different seat, and a bigger screen. All these are best obtained after-market.
Have fun.
Simon