With your range of lenses I would go for the OM-4Ti (UK model) as Ed suggested, but with a winder. This would give you a larger body and a good grip for your left hand, leaving your right hand free for the controls. If you decide to go down this route do be careful. In the UK the original OM-4 had battery problems. This was corrected with the introduction of the Ti model (UK) and I believe the T model in America, but do check out the US version as I have no firm knowledge of this. I use OM-2, 2N, and 4Ti bodies, the latter is without doubt, my favourite.
Thanks Allan. OM-4Ti is definitely a great option to explore. Here in US the T model and I already own the winder, I just need the grip strap for extra comfort.