they will acclimatise to harder conditions, most of the fish are wild, if you can i would suggest trying to find a fish that has been at the wholesalers or a LFS for a while and asking them what the shops water parameters are there, try and avoid a newly shipped fish, or if you can ge the fish imported to your LFS and pay for it and get them to hold it in their tanks for you for a couple of weeks to acclimatise it for you, just in case it goes belly up on you if you are worried but i have never had any trouble with them just give them a hiding place and they will be ok. that water temp sounds fine to me.