In reply to thedevonshirepiemuncher:
For your body to get stronger, it needs extra resources to build up your muscles and tendons. If you are losing weight, you are essentially operating on a deficit of resources because you are burning up your reserves. This makes it quite hard to both get lighter and get stronger at the same time. There is a lot of information out on t'internet about training and getting strong while a little heavier, then losing a bit of weight, then doing your long term project.
If I were in your position (and I am!), I'd lose the weight while sticking with a medium intensity workout _then_ work on getting strong after that.
I've never used a weight belt/vest and it's very rarely that I see others using one, even the guys climbing font 8s mostly don't use them so I would skip that.
Also, putting something into Google like "climbing weight loss getting stronger" will give you a huge number of articles, written by people who actually did their research, that are more comprehensive and more authoritative than the random opinions of punters on UKC