SOG has a couple tools that has a lot of what you're looking for. A friend of mine bought one purely because it had a punchdown tool built into it. Also, the SOGs are 'customizable' as well. You can buy other tools and swap them out. They have very strong pliers and cutters. Although, they are large tools, and I don't think I've ever seen one with a pocket clip.
(I'm a Leatherman man, but have a Powerlock in my collection.)
Depending on how handy you are, there are people out there that have done some crazy mods on the various multi-tools. I've seen MUTs with scissors, all kinds of bit drivers added in, pocket clips made, etc.
Oh, the new Leatherman OHT has the replaceable wire cutters. It might be a bit slimmer than a MUT, although I don't see a pocket clip on it either. I think it's a cool tool cause it's supposed to be accessible and operatable with one hand. Which, comes in handy in a situation like yours in a tight space.
Oh, and one more suggestion: Your MUT does have a carabiner on it. Not perfect, but you could clip it to a belt loop when you go crawling in somewhere...