A mix of wood is a good suggestion.
If you go with willow and popular you may have to think of how much you need to harvest.
There is a table on the www that compares the thermal output different woods.
You may have to give some serious thought to the following.
1. Quantity you will need to harvest and how to get it back to your store.
2. Size, aspect and wind flow of covered outside store.
3. An indoor store or a good route into the house with arms full of wood is important.
The above sounds simples but if you need to store 3 tonne of wood per year then you have some serious haulage and storrage issues - even if you stack the first years wood harvest outside you will probabley still need a very large undercover store for older wood that is drying and even older wood that is ready to burn.
Indoor store - if you are burning popular then how much a day do you expect to carry into the house? If you have space in the house to store a days worth then a few wood runs in the morning may be better than having to sclapp in and out of the house all day and night.
Right - off to get some more wood from outside now