temporary

I need to cap off two angle stops "temporarily". They need to be rendered unusable for permit purposes, then later restored. What's the proper cap to ask for a plumbing supply house, for those compression fittings? I'd prefer to leave the angle stops in place, and cap the outlet side.

I have to install a new kitchen faucet in a tight space but cannot do so without temporarily removing an existing Insinkerator 500 garbage disposal. Will this removal and reattachment be relatively easy to do or present possible difficulties. Thanks for your help!