X5 Wheel/Tire upgrade advice

[ulstr]

Hi Xoutpost forum, I am new here and was hoping to get some advice on the proposed setup I am considering for my 2012 X5 35i Platinum Grey Metallic

I am by no means an experienced modder but would like to enhance my wife's X5 with some simple tweaks.

Here is what has been suggested by my local custom shop:

1) M-style fender flares
2) 20" Beyern Spartan black or BBS SV Black Diamond Cut wheels/rims. I like the look of the black Beyern's but I am concerned with the rough road conditions here in Alberta (lots of gravel) they may get chipped, any advice someone can offer regarding the wear and tare of black rims?
3) Non Staggered tire/wheel configuration, the sales rep advised me that there are less options for the staggered setup and the ride may be rougher for my wife to get use to. Instead of a staggered setup he suggested using staggered offsets for a more aggressive stance. I am a big fan of the staggered look and have no experience with using offsets, again any advice? will I regret not getting the staggered setup with the fender flares?
4) Tires; Size 275/40/20 all around, is this good or should I be going wider? as for tire vendor the following were suggested, Bridgestone, Dunlop and Pirelli. I assume they are all pretty much equal, I was leaning towards Dunlop or Pirelli as bridgestone seem to generic

Feedback is welcome...

One item that was not suggested was running boards, after viewing alot of the pictures submitted on this forum I think these are a must. Can someone suggest a part number or provide a link?

Thanks guys, I am really enjoying this forum, any advice would be appreciated.