scswift:
Since then I've settled on either the 644 or 1284, but I won't know which I want to go with until I write the code and see if I really need the extra ram.
Why not just decide on the 1284 and be done with it? Surely the extra $0.23 isn't going to kill your BOM. (In fact the 1284 is CHEAPER at higher quantities.)
scswift:
Option 2 is to do the same thing but store the tokenized code in ram.
Alternately, you could page the script into RAM if it was at all linear.