You need to use the sportwerks .26 backplate that is a perfect fit on the SH .28. No modding required. Next, you need to take out th 5mm or so spacers off of the engine mounts. Then you can lower the engine, and move it closer to the center.
I use the OFNA 12 Volt chrome top starter box. I haven't had any issues and the box starts up most motors. It's cheaper than the truggy box, and it's universal.