either nimh or sla should be fine as i doubt the photo frame and leds will draw much current. a high amperage sla or nimh should be more than capable of supplying the amount of power required for 30 mins+. nimhs have the advantage of weighing less and charging faster although are more expensive than sla's. if you have the cash i'd go for nimhs but if you don't want to spend that much and k9 can support the extra weight of sla's and you aren't too fussed about having a charging time of an hour or less then go for sla's.