first of all petco is one of the worst places to get a reptile, especialy geckos. i admit some of my girls and boys are from there but i have gotten really lucky. my other geckos who have passed on a while back where from petco and died probably becuase they were disseased infested. also all the petcos arround my area in so. cal. never take care of them and i have been to many of them if different counties.
okay second of all: you need to keep any new animal quarantined for at least THREE MONTHS before introducing it to another, or have it checked by a REPTILE VET, not just a cat/dog vet unless they also specialize in reptiles. a lot of the time, regular vets dont know anything about reptiles.
Third of all: yes another female would probably be okay. a male would probably give you babies and if you are ready for maybe up to 16-20 eggs and have incubators and extra space, go for it.
fourth of all: introducing one male to one female can work, FOR A FEW DAYS! the male will probably breed the female to death. this means the male will probably continuosly breed to the female causing major stress and lead to not eating and then death. a 2 female to 1 male ratio would be better.
okay im not trying to sound harsh. just wanted to give some GOOD advice.