Good choice for 20' XLR cable?

If you're not afraid of buying from Ali-Express, I personally have bought cables, ICs (XLRs) and PCs from them. It's very hard to beat their prices v quality. I bought a variety, one in particular is  Xangsane hifi xlr cable 4N pure silver 2 * 0.5mm ² amplifier sound card decoding connection cable microphone cable 3.5M $445

https://www.aliexpress.us/item/3256807288169672.html?spm=a2g0o.productlist.main.27.22bf796aX71qWn&algo_pvid=b73d923e-224a-499a-8425-127a2d831e93&algo_exp_id=b73d923e-224a-499a-8425-127a2d831e93-13&pdp_npi=4%40dis%21USD%21181.99%21165.09%21%21%21181.99%21165.09%21%402103209b17360262854955412e0336%2112000040902363078%21sea%21US%21128321401%21X&curPageLogUid=8k8CnKx3h6og&utparam-url=scene%3Asearch%7Cquery_from%3A

Blue Jeans Cable offers several cable options and custom lengths for a reasonable price https://www.bluejeanscable.com/store/balancedaudio/index.htm#1800F

I also recommend Blue Jeans cable.  They will make cables for your specific length.  Their customer service is excellent.  Well made cables and connectors assembled in the US at a reasonable price.  No snake oil.  I can say the same about Pine Tree audio.  They both will work with you online to answer your questions before and after you buy.  It’s good to have Choices.  

Yes for Pine Tree! I had them make me a custom length Phono Cable with my specific fittings (rca/din connector with long narrow neck to fit the arm’s long narrow tube). They were very helpful solving, making, promptly shipping it.

I mentioned the inexpensive find from Amazon above because I bought a cheapo 6’ phono cable from Amazon while waiting for a high priced much respected Ortofon Phono cable and the Pine Tree Cable.

Frankly, the $6. cheapo phono cable from Amazon sounds the same as the Ortofon and Pine Tree.

If you hear a difference, great, pick the preferred, I just think, with easy returns, a well made inexpensive cable from Amazon for comparison is easy and can potentially save you a lot of money.

Ali-Express, Temu, eBay from China or Japan, Yahoo Auctions, aleado from Japan: I have successfully used them as well, just pay attention to all the details, and watch the shipping cost as you select. Temu, you can pre-filter 'local warehouse', so the item is already in your country, you get it quickly, and returns if needed would be local.

Yahoo auctions: 1st you make an account with aleado with enough money already in it to cover your bid amount. 2nd: seller ships to Aleado (that cost is shown when bidding), 3rd: they give you several shipping methods with exact costs after they receive and inspect the item from the seller on your behalf. (there is a shipping calculator to get estimates for your address while bidding).

I would give this some serious thought. What are you using now and what would be the cost of buying long runs of your current cables? I have used short runs of Blue Jeans, Nordost knockoffs and Benchmark, but they were easily bested by other brands.