I bought one of these:
https://www.amazon.com/Anova-Precision-Cooker-WIFI-Watts/dp/B01HHWSV1S/ref=dp_ob_title_kitchenIt's a sous vide cooker, which means you cook (primarily meat but does eggs and some veggies too) in a water bath. We like this so much, we took it on vacation with us.
You do not need anything but a pot, water, and freezer bags. You put meat in the bag, lower the bag into water until the top is almost covered, get out as much air as possible, then lower the bag into the water. You then cook the meat for the desired time period, and then sear the outside using a grill, cast iron, or the broiler.
This cooks so well, that we no longer cook steak, lamb chops, leg of lamb, or anything else where tight temperature control is desired, with any other method. Also, you can prepare the meat, put it in the cooker, leave and come back and sear it. You can also program this, so you could put the meat in an ice bath in the morning, and come home in the evening to meat that's ready to sear. (I have not actually tried this yet.)
If you see this (or a competitor) on sale on Black Friday, buy it. I'm thinking of buying another, to cook breast atone temperature and thighs at another, or to cook a portion of meat at a higher temperature for those who don't like red centers.
Other notes. A vacuum sealer does help. If you set the temperature for rare or medium rare, the entire piece of meat is that temperature. This means that people who don't like meat at that temperature don't have a choice. If you cook in the oven, the ends are often overcooked/not red, but not with sous vide. I originally cut a hole in a cooler to use with this, but now we only use that for long cooking sessions. We bought a relatively short plastic container to use for short time periods. With sous vide, the cooked meat does not have to rest, and you don't have to worry about cross-contamination (you can use the same plate to transport the meat to and from the grill for searing). There's a wealth of information out there about cooking times for different cuts of meat. As of now, we've not actually used programming of this device; we just set the temperature manually. So, I think you're safe getting the cheaper model (not sure how much difference there is going from 900 watts to 800 watts, though). I always had trouble getting things like steak and leg of lamb to cook evenly on my ceramic grill --- part was always overcooked. With this, the meat is perfectly cooked. I do miss the smoky favor though, and since you only sear for mere minutes, you can't get smoke into the meat.