I have two simple question that are, what 3x3 cube should I get and why? I am currently using a Dayan Zhanchi in which I am looking to replace. I have a personable best solve of 19 seconds with and average of 25 seconds. My other question is what is a good lubrication I can get with the new cube?
The problem is that there is no simple answer to your simple question. The lube one yeah, you can get either Maru lube if you don't want complications or silicone oil (traxxas, lubicle, thecubile, ... there are many) if you want to take your time to take the cube apart and lube the core and the pieces in a way that will last more than Maru. If you need more help with this you can ask specific questions in the Lubrication Thread.
But regarding what cube to get... do you like your Zanchi? Do you want something similar or different? Have you tried any other speedcubes that you might or might not have liked? Because right now there are so many good cubes out there that there is no "one size fits all" answer. Even the list of top cubes would have more than a dozen (Aolong, Weilong, Chilong, Yulong, Sulong, Huanying, Liying, Yueying, Gans 357, Guanlong, SS Aurora, FS ShuanRen, there's also a new Fangshi that I don't even know the name, the new Yuxin (I just got mine so no formed opinion on it yet).
If you can be more specific on what you would like (and how much you would like to spend) we will be able to help you better.
EDIT: The new Fangshi is the Guangying, by the way.