compressor

So, I need some advice on air compressors. I was planning on buying used, but honestly I don't trust the meeting someone off of craigslist in a parking lot when I cant tell if it works or not. I went to a few pawn shops and couldn't find any the right size. Now I am planning on just...

Hey guys, Was just curious if any of you have fancy compressors or tools you have made for compressing the valve springs. Just looking to get a few ideas.

I'm looking for a air nozzle or ( air gun ) for my compressor that is narrow with a very small tip for blowing out holes ect. has anyone seen or made one?

Can anyone recommend a good choice for a valve spring compressor? I checked all of the local auto parts stores, and none of the choices look like they would fit the recessed spring design.

Can I just run to the hardware store to pick up a bolt to use temporarily? I ordered the new valve but it may take 6-8 weeks. It looks like the valve drain is 25/64 but am unsure of the thread pitch. Is this a common bolt size?