arduino atmega logger project

I want 4 analog in 4 digital in 2 analog out 2 pwm out 2 digital out 32K byte memory (23K256) 1 real time clock cpu atmega 328-p-pu project description stage A =========== basically it’s a simple logger whenever there is a reading in analog or change in digital the program analyses the data and decides whether to write to memory or not and if to output to out pins or not (considerations are percent of former reading or difference from 10 former readings, or nothing such as POWER ON event ). the program and the design can be made on arduino uno BUT ! the design should be very carefull to consume as low power as can be! the outcome of the design is not only a diagram and a program but also a printed circuit design as the product is not arduino but a special PCB. option should be made to use SD instead of the 24K256 chip data structure for writing events will be given later stage B ===== another arduino will be connected via serial to the card in stage and they both will talk between them moving data from and to the card this second part will have LCD USB+clock chip and SD to which it will put the data collected commands will be given later (basically it is get clock from card ,update clock from arduino LCD , read data from card write data to card , delete data form card) no pcb here