I need a longer lens

Ha, I knew I'd get more than one entry here in February, albeit it 25 days apart but whatever. Headed down to Red Wing last Monday around 1:00 to see if the eagles were out. They were, but my kit 80-300mm just doesn't cut it. There was an incredible photo op as a lone eagle did two laps around the boats in the bay at Colvill park. Thing is is that it happened right after I pulled in and my camera settings were still set from low lights shots and didn't have to time adjust them and get setup before the big boy was gone. FUCK! Spent the rest of the day trying to take pics of eagles and hawks that are way too far away for my crappy kit lens. Still pretty fun though, pics dont break a trip that's main goal was just to get away for the afternoon. Good pics would've just been a bonus. After I got home and realized my pics turned out like shit I went on BH to look at new lenses and teleconverters. Unfortunately Olympus isn't like Nikon or Canon and doesn't offer a huge variety of lenses, but I think I found a decent lens for a decent price, a hell of a lot better than the one I have now. Won't be getting it until next offseason but I definitely want to get in to bird photography. The lens is an Olympus 70-300mm (equiv. 140-600mm due to the 4/3 system).
http://www.bhphotovideo.com/c/product/504906-REG/Olympus_261057_70_300mm_f_4_5_6_Zuiko_ED.html#reviews
Combine that with a 2x teleconverter and we're talking some serious zoom. Probably have to pick up a monopod for it, but that will likely be my big purchase next offseason, unless another telephoto lens comes out for a decent price.
Anyways, here's the proof that I desperately need a better lens: