I'm in the market for a new bag... I have used the slingshot AW 300 but was wondering, is there any other sling-type bags? I am open to over the shoulder bags too. requirements? fit: 2x Cameras (1 with lens attatched) 4-6x lenses Extra space for more accessories. plan on getting a 70-200mm so... advantage if it fits a laptop too. the Pro runner AW 400 seems best so far as it seems the largest but... not a sling.