[amsat-bb] Where can I buy pre-made feedline?

I'd like Belden 9913 with PL-259 connectors pre-attached, 50'. Ham Radio Outlet (every store) is out of this, and so they sold me 50' bulk cable and connectors. I have been trying VERY unsuccessfully to solder these, but I am unable to do it. I can sold 0603 SMT resistors and 0.5 mm pitch TQFPs, but not this.

I have tried multiple techniques. I am no longer interested in trying to solder this.

Google has been less than helpful in finding online stores.

Can someone point me to a reputable online retailer who can ship this to me immediately? Thank you!