Buying a Slow Cooker, Recommendations?

I'm looking for a fully programmable slow cooker without a teflon coating. I am not sure being single and living by myself if a 6 quart is too much but I was looking at the Hamilton Beach 6 quart 33969 set it and forget it or the Crock-Pot SCCPVL610-S.

Biggest issues: Is 6 quart too much for just me one person, even if I plan on making it into multiple meals over the next few days?

Are there slow cookers that have the ability to do High for X hours, Low for Y hours then go to warm? That'd be great for when I'm at work for 8-10 hours.

Some other questions: Is it worth it to get one that can be used for cooking on the stove as well?

The plus of the Crock-Pot seems to have the added ability of being able to cook for up to 20 hours which would be nice I think for something longer like Shabbat Cholent or anything else that requires a longer cook time should I want to try that out. I'm not sure of the Hamilton and the longest cook time it allows.

I want something that I can use currently for myself and not have way too much food that gets wasted - I figure I can make that issue go away by just adding a ton of vegetables to it and since those aren't that filling shouldn't be a huge waste of food or money. Then if I end up cooking for 2 in the future I have the size for that. I also want to invest in a good one that I can learn a lot with so versatility is a plus. One route I was thinking of going with that was the Fagor 670040230 3 in 1 - acts as a rice cooker, pressure cooker and slow cooker.. but has the Teflon coating. Not sure if there is one that can will fit all of this or if I should get a smaller one now with some features and then a bigger one later that has other features. I currently have a small crappy 1.5 quart one that is manual. Ideas?