Thank you but I forgot to mention I do not want to rely on any static source(s).

I want to bootstrap into the p2p network and pull the info out of there.

I also don't want to store the whole blockchain in the process but only the last N blocks. Also the possibility of offline time is possible so it should be able to somehow query only the last N blocks even if the last block it has is N+x (x>0) away.

Sorry I wasn't clearer, I was in a bit of a hurry.