Where do you obtain these flashes from Phil? The UK Godox shop lists the TT685 at £129 and the TT350 lists at £90, each with a 2 year warranty and excluding the wireless transmitter, which is another £34. I can see they are cheaper on the likes of Ebay and Amazon, but are these being shipped from China to order?
I know that the Olympus/Panasonic optical flash system is never going to be as good as a wireless arrangement, but the R versions of the flashes with work directly with the onboard flash of virtually any Olympus M43 camera and later Panasonic models from the GH3 onwards, straight out of the box. The Nissin i40 for M43 will also play nicely and is especially compact, lightweight and with a brilliantly simple beginner friendly interface, some are appearing secondhand and my wife uses one on her Lumix G3.
Out of curiousity, I weighed my FL50R which Olympus claims weights 385 gms without batteries. Mine actually weights over 500 gms with the included diffuser and batteries, there's no denying this is a sturdy and heavy unit but might withstand a few knocks reasonably well.