Side Steps and 3rd Row Seat

Hi, I'm just trading my 2004 G270 in for a 2007 G280.  It's basically a ruggedized military version.  It's my daily driver and my clients struggle at times getting into my G270 and I think the G280 is about 4 centimeters or more higher. I'm wondering what sort of truck type steps are available that wouldn't damage the integrity of the vehicle?  Any ideas?

Also, this G280 has 4 seats.  Occasionally I need 5 seats with the additional seat needed for a child. I see that there are tie down rails on the bed.  Any ideas for a 5th seat on the sides or rails with a seat belt?  I've seen some flip up seats but they seem a bit overpriced.   Removeable would be best. 

Thank you in advance for any info you can provide.

Best,
Steve