should i top or not

i have 8 northern light feminized from seed theyr 25 days old about 30-35 cm high ,my plan is to clone as much as posible and if i top them now and transpant to a bigger pot at the same time will i delay their growth to much or maybe gain a bushier plant whit more clones

I would not top them. What ya want to do is take some of the spindly branches off the bottom of the plant. Use them for clones. Less branches on the plant will get ya big fat colas. If ya have a shit load of branches on the plant ya will get a shit load of little buds. With less branches all the water nutes and so forth goes into the remaining branches.

I would actually top them.. i always top my potential mother plants twice, this gives me lots of side branching and bushiness.. thats just my opinion

and if properly transplanted, there wont be any shock, topping and transplanting wont kill or harm your plants that bad so go ahead, in a week you will have a beuty mother plant goin