I really like the Silky Zubat 330mm for a larger saw. It will handle 6-8" logs, if need be (larger if you can rotate the log or move the saw while cutting). Hardened to R 67, hardchromed blade for lubricity/corrosion resistance, weighs a bit over a pound, will fit in a daypack or hang on belt. To me, it feels a little more stable than the giant Silky folders but I'm sure they'd be fine too. Another nice feature is no assembly required when you want to use it. Just pull it out of the sheath and let 'er rip.
www.benmeadows.com and www.knife-depot.com tend to be a bit cheaper than the Silky factory store.