With nothing more than a quick Google search it is apparently possible to convert the M3 Simply into R4 and back; but I don't have an M3 Simply, I have the M3 Lite- which apparently no longer updates. Is there anyway to convert my system or update in another manner?
The conversion inbetween the M3 and R4 is only possible on the older models. I tried it on mine but the solder points are not there. As for your M3 lite, I think your outta luck.
Don't know much about either of those cards, but you can try http://www.shunyweb.info/convert.php# if you haven't been there already. It's worth a shot.