1)How do i calculate the size of the required power size for this box? Would a 500ma 12v do the job?
Should be OK with 2 LDCs without backlight (Or with one LCD with backlight). If you use big LCDs (2x40) with backlight better use a 800-1000mA spply. And better get a 9V supply as the voltage regulater will get hot with 12V.
2)Can i use a 100V / 1 Amp rectifier for the cores? Its the smallest voltage i can get locally.
Yes, thats OK. Higher maximum voltage is no problem.
3)Also…If i only have 1 LCD will that be ok? Is there a benifit of having two displays (one for each core)?
Sorry, I’ve used linked cores only in MBSID so I cna’t say anything on this. Someone else?