I have seen one simm that was double the height and single sided, instead of being double sided, but I can't remember if it was 128mb in size. Unless you can get a double sided simm that uses extremely thin chips, it will not fit in the Blizzard 1260, unless your 1260's simm socket is different than mine, which holds my simm flat against the 68060 CPU.
I do not try to close the A1200's trap door cover on my A1200 so I have considered putting some 1/4 inch feet at each corner of the bottom of the A1200 case to raise it off the desk and having someone remove my flat simm socket and replace it with an angled simm socket on my Blizzard 1260 card so my simm module will no longer be resting against my 68060. That would allow me room to install a thin heatsink on the 68060 to keep it cooler and remove the heat from the 68060 transferring to the RAM chips.