Hi,
awww you're so nice! Trying to give your two guinea pigs the best possible life is so sweet and caring. That hutch looks great for its value and I wish i'd seen it before I brought my hutch 2 months ago.
Go on this website:
http://www.guineapigcages.com/toys.htm
It's not one of those websites where it advertises stuff to buy but it shows you toys for your guinea pig you can make for example towel tents and tunnels. It's such a good website it tell you how to make C&C cages (which if you didn''t already know are like the best cage ever for guineas) and it shows you how to assesorise them!
I know you don't have a C&C cage but you can use the same principles to your hutch. Also that hutch has a built in run so make sure you move the hutch frequently onto fresh grass (evrey week or so). Also position your hutch against a wall incase anything tries to knock it over.
And when it comes to winter buy a plastic hutch cover and add way more bedding!
I have added a shoe box to their living area which I cut the bottom of and a little doorway. And I put the foodbowl on top of the box so they can climb up so it's like an adventure. They dom climb up because all the food is gone in the morning!
Also add tunnels by buying one from a petshop or getting one of those plumbing tunnels at DIY shops.
Okay hope this helped, try hiding food around the hutch and on top of stuff for extra fun. Good luck with your new piggies but beware if they are female. I got my 2 females from a breeder a month ago and the white one has had 5 babies (one died yesterday snifffffff) and the other one is pregnant! So please make sure if they are females you've got them before they are 5 weeks old.
Good luck!