What's the best way of training for eventually doing pullups at home, for someone who's currently far away from doing pullups?

I have built what I consider a decent base of strength (500lb deadlift and 225lb ohp) but I need to lose weight massively (currently 6'2" 350lb and want to get to 215lb).

In order to get me where I want to be, I've decided to put absolute strength into "maintenance mode" and set a goal of strength-to-weight ratio, and I thought being able to do unassisted pullups would be a good long-term goal for me. Obviously it will require significant weight loss while maintaining strength. I feel like (based on absolutely nothing), I should be able to get pull ups at around 250lbs.

Today I mostly train with clean and press in EDT style, if that makes sense. Then I hit the other Dan John movement patterns for maintenance and practicing the movement. I have barbell, landmine, kettlebells (up to 106lbs), a TRX, and sandbags (85 and 150lb). I don't have a rack or bench (sacreligious?).

What kind of rows or other exercises can I add to help prep me? I feel like those rubber band assisted pull-ups are really awkward to do and setup -- I might even need two bands (I've never got the advertised level of resistance from the bands when I've tried these before), and I don't think the TRX body rows really do anything that I can feel.

I'm willing to buy minor stuff, I was looking at a T-handle for the landmine, or a [Rickshaw Farmer's Walk](https://www.titan.fitness/strongman/carry/farmers-walk/rickshaw-farmer%E2%80%99s-walk/429993.html) (this is especially justifiable because it would be multipurpose). Or I could just get a bench or some other kind of support and row the big kettlebells. But these are all horizontal rows -- how much of a difference does it make?

Obviously a lat pulldown type machine or something like that would be ideal, but just not looking to spend that kind of money.