what exactly is a gold dat? a strain of indo dat?
anyways
theres nothing you could really keep with it permanently as of right now unless you grow them seperately as the datnoid will eat most tankmates you could keep with it now and other tank mates that you can that grow big often grow faster like endlis and arowanas
i would say maybe a scomb payara or red tail as they also grow slow however NOT armatus those grow similarly to arowanas and will eat the dat
something safe 100percent is a flagtail tho