Cap kit is kinda a pain because caps on every board need to be replaced as part of the kit. Two of them sit under the large heatsink assembly on the power board so it has to be completely removed to get to them. THe debuzz kits...ehh.. the one I got from Console5 works well but it was kinda a booger to get installed. Requires cutting some traces and rerouting things with replacement components plus the small perfboard for the audio to go through and back out. The one that Charles sells (Once they are available again), looked to be pretty easy. I think he may have even come up with a no solder required option in the kit, though still advised to solder everything in I'm sure. Basically you disconnect the speaker from the main pcb and plug into his replacement and I believe the original speaker connection on the main PCB he provides a new wire so you connect that to his new board. It totally filters everything out and provides a clean audio output through his replacement board. That is a simplification of it, but you get the idea.
He is making another kit that will have a break out box you plug as needed that will make it easier to incorporate the VecVox and mix it with the audio to a new audio out. And he is developing that box to be near studio quality. Though I'm not sure why since we are just talking the vectrex here but still pretty darn cool.
And yes some jitter is normal. Is the entire screen jittering, or just some of the vector lines? If just the vector lines, then you might consider getting the Integrator replacement caps from console5 as well. If the whole screen jitters a bit, that is pretty normal in most cases.