I've assisted with a couple of KE30 rotary conversions, with 12A, the mounts we used were supposedly also good with KE70's as well.
We used standard KE steering? Didn't have to touch it, sump fitted fine, but the mount kit we used (and my mate fabricated) mounted the motor quite far forward.
It was 3 piece kit, the crossmember to bolt to the motor, and 2 plates, which bolted into the chassis rails, pretty much underneath the radiator. Very simple, but I wouldn't really recommend them if you're making a top quality job, as the handling was kinda odd with so much weight forward.
The KE had factory brakes, and a TE71 drum rear end, with the mounts adapted to fit the leaf rear.
The gearbox mount was made from bits and pieces of both RX7 and KE70 mounts, and bolted into the factory holes, with the shifter hole having to be slightly lengthened to get enough clearance around it. Not sure about the driveshaft, I recall being told it was the RX7 item, and had bolted up to the TE71 rear, but I can't guarantee that, I didn't see him install it!
Hope that helps! I don't talk to the guy anymore, he's a dropkick, but if you're seriously wanted to get started, I'd maybe talk to Al Marsh or Brian McCahon at Rotary Research, but don't waste their time, they don't appreciate it!
Gd luck!

Daily driver: Toyota RunX/Toyota Caldina
Ex: 2x AE101, 5x KP60, KP61, EP71, 3x KE70, KE72, AE70, AE82, 2x TE71, AE90, AE92, ST170, plus 11 Hondas, 12 Nissans, 6 Fords, 4 Mazdas, 3 Mitsis, an Isuzu and a Lada!
