On infinite limbs: Yes, but limbs can be designed with reasonable interchangeability. Hands are good as is, but with a little extra design, they could turn into passably good feet - and arms/legs even have the same number of joints, they just appear to bend in the opposite directions (knees bend forward, elbows bend backward) so they would need slightly different types of installation - or those joints could simply be made to bend both ways. Freaky, but works (and, worst comes to worst, can always be programmed not to bend in a wrong way to spare the human mind).
What I don't like about this idea is that, apparently, if you lose a forearm on a mission, and the team leader/local medic decides to replace it with prosthetics, you'll get whole rest of the arm cut off to fit the 'arm' prosthetic. Maybe that could be solved, but I don't know; I'd like to save every inch of my flesh if I could.
On Kugelblitz: That looks good, but don't you want to tinker with it a bit more? For example (and this I had been thinking a lot previously, too bad I don't do deathtubes), one could try lining gauss barrel (or even railgun, normally far too easy to damage with wear) with frictionless material - we have several lately. What kind is the generator? Specify that you are using a cheap generator from RC's 'Advanced Generators' project. Saying that you use the new fuels is self-obvious, but still specify so - oh, and you might decide to use Sean's new plasma-thrusters (they appear to be a bit slower, but has larger effective range and even cheaper, IIRC, which might be just what you want).
Specify how and where you cut down on the resource cost and use newer, advanced tech, or it will likely be ignored and forgotten. Bringing the price down is an engineering problem, so approach it as such; don't trust the Council to be all nice and good and give you the low price you deserve. Convince them through the force of reasoning.
And finally, before anything else, run this by Piecewise to get a rough resource cost estimate. Whatever they might say, I wouldn't trust them to decide a resource cost - they are in the job of balancing, and balancing comes after the resource cost; knowing them, I wouldn't put it past them to slap a HGC price on it and call a day. A freakin' outdated, obsolete-tech, inefficient-design HGC - simply because it fills a similar role, and as such has to have a similar price.