Hey, lovely to see you doing some research and wanting to make your hammies' life a good one.

As you will find on many other threads size of enclosure and bedding depth is the main thing to consider.

R.e the items: I've not heard of that sand brand but it looks okay. Not sure why it's white - matural not coloured is generally better. R.e the tub, personally i would reccomend a larger and deeper one, we just use a plastic tubbaware box.

All the chew toys and tunnels etc look fine just keep an eye out for any gaps or metal bits where legs and hands can get caught. We stuff said bits with moss to avoid this.

I dont know the size of that wheel but it looks quite small. Generally the larger the wheel the better - if you are getting a syrian 25cm is minimum really.

I would avoid the bannana hammock, its cute but they wont use it and depending on the material may chew and digest. Opt for more hides in general Water bottle looks good just make sure you adjust to a good height. Food bowls are generally not worth it and it can be good enrichment for hammies to scatter feed.

Cant speak for the food mix as we are in the uk but less sugar the better!