I've made up several XLR>RCA cables which is real easy (if you can solder at all).
I've been using Mogami 2549 and Switchcraft XLRs which was recommended by Paul Stubblebine here a long time ago. Although I won't say they're the final word in any particular sonic category, they are competent and cheap as all get out.
If you make your own, you can also change the absolute polarity which is different on most Otari's. That would put pin 3 hot to the center pin on your RCA. You can tie the shield and pin 2 together and connect one to the sleeve of the RCA.
I do have some cables made with the Mogami 2534 and I think the 2549 is better sounding.