Glad to see so many other Olympus OM users here! I've used OM equipment since I got my first SLR back in '83 (an OM-2n). My current hiking/outdoor setup consists of 1 OM-2n(the same one), 1 OM-1n (Backup/Need the mirror lock up for the absolute sharpest images), T-32 Flash, Zuiko lenses - 24mm/f2.8; 50mm/f1.4; 50mm/f3.5 Macro; 35-70mm/f3.6; 200mm/f4; 300mm/f4.5; plus a Hoya 135mm/f2.8 (nice, very sharp lens); and a Sigma 500mm/f7.2 APO. All of this fits nicely into a Lowepro Rover AW II pack (with the 30mm and 500mm lenses in add-on lens pouches) and a Manfrotto 3001BPRO tripod with 3030 head straps to the pack to complete the picture. The top compartment of the pack has plenty of room left over for filters, film, spotmeter and lunch.
Be careful getting started with Olympus OM gear, the dangers of becoming a Zuikoholic can put you in the poorhouse rather quickly!