Based on the photo you posted, Ironman plates have you all set for a DC shaft as it appears your driveshaft is aligned wih the pinion.
What you need is not really an adapter but simply a spicer (don't accept a foreign replica) 1310 Double cardan joint which any driveline shop worth it's salt should stock and be capable of welding onto your toyota OEM shaft after they cut your existing yoke from the T-case end. So, your shaft will retain the OEM style yokes and joint at the pinion end and have the spicer DC at the T-case.
Be advised, Toyota drive shafts are infamously strong and over built. The spicer 1310 DC Joints will be a bit smaller but you have two of them carrying the load. You can see what my rig is in my signature. I wheel Rubicon and such regularly, because it's where I live, and I have had no problems with this shaft which I had built by a well established shop local to me.
Some of our members like to use a rear DC from a Tacoma IIRC and that is great too and perhaps even stronger than mine.
Have you talked to Landtank about a DC shaft?