Best mattress for side sleepers | Size Mattresses?

I'm not sure what you mean by "side sleeper". People roll around while they sleep. They have to roll to keep blood going to all parts. Mattresses are not made to cater to your sleep orientation, only your desired softness or firmness.

Considering the prices asked for mattresses, even bad ones, it is prudent to buy the cheapest you can find and throw it away if it does not suit you. That would be an air mattress. They are not sturdy enough for regular use. A good air mattress is one that lasts a few months. So you pay 60 bux for a queen size Serta Perfect Sleeper at Walmart and it springs a leak in 6 to 12 months. Your snooze has cost you 5 to 10 bux a month and it has been wonderfully comfortable. Just add some air to make it firmer or let some air out to make it softer. Regular mattresses cost a thousand bux and you are stuck with whatever firmness they were given at the factory. You have to sleep on that brick for 200 months to equal the cost of an air mattress.

TIP: Get an electric blanket to put under your air mattress. A twin size blanket perfectly fits a queen size mattress.

TIP: You want your mattress at least 80 inches long. That happens to be the exact length of a queen size mattress.

TIP: Get a thick blanket to put UNDER the mattress pad so you have some air space between you and the vinyl.

TIP: Be sure fitted sheets are rated to fit a mattress 17" thick. Most are not.