I decided on the saddle first (AH Kestrel). They don’t make that anymore so you’ll have to find something you like. I also see Cruzr mentioned a LOT lately on here.
Next, choose your climbing method if you haven’t. Sticks are easiest IMO and if you’re used to hang-on stands, you’ll get it right away. I bought a Predator first because back then it was the only commercially available platform and I didn’t want to use ROS because again, I was used to hang-on stand and I have arthritic feet so tree steps are not the most comfy for me. It’s a great small platform. Now I use a Trophyline platform (the big one lol) and I love it. Worth the extra couple of pounds on private or all-day public.
Ropes…DO YOUR HOMEWORK. Please. Real homework. I call every single company I’m planning to buy life-support or weaponry/broadheads and knives from, I plug into their knowledge of the products they’re selling and I’m honest about applications I plan to use their products for. I get ropes from Tethrd (I like 11mm and 8mm) or Wesspur. Sometimes REI or Amazon if I know what I’m looking for. Most companies really appreciate questions and feedback especially if you can get a human on the phone, and your greatest safety resource other than an actual climbing instructor is the people who make your kit.
That said, there ARE companies who are not as knowledgeable about what they push/sell as others, and I encourage you to go through them with a fine-toothed comb. Some reputable saddle companies from my own experience are AeroHunter (sadly closed), Eastern Woods Outdoors, Wesspur, Trophyline, Novix, and depending on the day or product, I really do like Tethrd’s gear overall and I can look past the saddle-bro nonsense to see what they have in value. They’re not always very responsive or quick to ship, but their customer service is generally manned by a human who is very nice and speaks great English (unless that ain’t your language). I would be lying if I said I didn’t trust their platforms, ropes, and straps. I don’t have a single piece of amsteel in my setup, so I can’t speak to that.