Most Lifeline providers offer a limited amount of bandwidth for your smartphone, however, if you have a computer, or if you find you watching Youtube a lot, then a home broadband internet connection is essential. Since every area is different (even in the same city), there is no way I can tell you who your choice or choices are. And yes, it is possible to have just 1 choice at your address. If you live by yourself, then a 50MBPS connection will suit you just fine. If you are going to use SIP?/VOIP? or Wifi? calling, you would need a latency of less than 100ms. Most broadband service providers will offer that, although you would want to inquire if you are using satellite internet service.
If Comcast/Xfinity is servicing your area, you should be able to qualify for Internet Essentials which is 75MBPS for $15/month. If you are on a tight budget, and I will imagine so with just SSI?, then the $15 per month internet service will be a nice line item in your budget. It would also save your cellular data for when you’re not home. If you have a smart TV/Adapter, then you should have internet at home to make use of the features.
If you don’t have Comcast/Xfinity, then your internet bill will likely be more expensive. I would recommend getting the lowest cost plan as possible. Internet is essential, but you might find it hard to afford the higher end plans.