I also got my 600mm without a great deal of planning and then had to face the problem of supporting it. I've got a Gitzo 1325 carbon fibre tripod and one of those Wimberley gimbal heads. You can get the tripod in metal rather than carbon fibre, which is considerably cheaper, but it's also a lot heavier and I decided than I needed to save weight wherever feasible. And it's just as well really, because the gimbal head is pretty heavy by itself, although I've got the original version and I believe the newer version is a bit lighter. Yes, it's pretty expensive and I have to admit that if I'd looked into it a bit more then I might have bought something else and saved myself a few quid. But having got the lens, I wanted to get out and take pictures ASAP!
Of course it's an excellent lens, you just have to work out a system for carrying it around that works for you. I've got one of those multi-compartment rucksacks which is good for carrying lots of stuff over long distances, plus I also got a custom made canvas bag from Wildlife Watching Supplies which enables me to carry it as hand luggage on planes. When out birding I carry the camera and lens over one shoulder via a padded strap (attached to the lens, not the camera) and I carry the tripod in the other hand. It's not ideal for making the most of quick opportunities since you've got to mount the lens on the tripod but it's the best way I've found so far. Then of course you have to learn how to get the most out of the lens which is a long-term, on-going task (one which I'm still very much involved in myself). Persistence will, or at least should, be rewarded though!