what dehumidifier do i buy for my 1,015 sq ft basement a 30-pint dehumidifier?

You don't one that is out of sight, that doesn't have the option for a direct drain, as the other guy stated. Go by square footage and whether or not it can be connected to drain directly. If you do not have a drain that can be used, buy a condensate pump also, so you can run it over to an open drain like for the washer or a sink.

It's early February, and many of us are using a humidifier to put moisture in the air. Whatever.
Sizing a dehumidifier for hot sticky weather starts with how humid it will get where you are. You also have a fairly large basement. Manufacturers typically give you square foot coverage right on the box, for the "average" customer, so start there, then go bigger if you are really anticipating really soggy conditions; it's hard to go smaller than 30-pint.

Meantime, many places will also be using air conditioning in season, which removes a lot of moisture. Some just use a dehumidifier in transition season, like a rainy spring or fall when there's lots of moisture, but no need to cool the air. Some will use both in hot sticky weather, as the dehumidifier in effect helps the AC. I haven't seen any data as to which way the total energy costs go, but I do know from experience that it gets the job done quicker.

Where I live, it can easily hit 90+F temp with 90 per cent relative humidity, and I'd use a 50 pt unit without hesitation, going solo without AC. I also get aggressive about any maintenance needs to keep basement moisture WNL, like poor gutter/downspout condition, bad exterior grading, cracked foundation, etc. That has pretty much eliminated my need for a dehumidifier.

I've gone on for too long already, but hopefully given you some perspective.