I used an isolation membrane with OSB and then engineered hardwood. It worked really well but if I could go back I would have spent more time flattening before putting the OSB down. It's pretty similar to the Dricore but costs a little less. Dricore is a great option too.
https://www.homedepot.com/p/ALINO-Da...LK50/312936504
If you're going the solid wood route it's definitely best to use a vapor barrier / isolation membrane and add a subfloor you can nail into. I would also consider keeping it unfinished. I find that the engineered hardwood is a little slippery once it gets sawdust on it.