Sourcing organic ingredients for hams can be tricky, it's not always easy to find the things they need that are organically grown, it's well worth trying to find them if you can but you have to balance organic with appropriate & variety within the mix.
You've obviously given this some consideration already but some things you need to think about are protein, fat & fibre content of foods, species appropriate foods & nutritional values, Syrians & Russians need slightly different mixes ideally & Russians also tend to need slightly more protein, needs change with age too, particularly protein.
I would be a bit wary of following any recipes you find online, I've yet to find any recipes or guidelines for making mixes that are really that accurate or well considered.
Basically you need to decide which ingredients you want to include then work out the amounts of each to provide the correct nutritional values. It does take a lot of calculations!
We have had a long discussion on this before and you might find this thread helpful.
Has anyone ever made their own hamster food?
If you still have more questions I'd be happy to try & help.
You could grow wheatgrass for your ham, along with other things that can be sprouted or grown they can be a really useful nutritional addition to the diet but I tend to feed things like this more as extras than a part of the daily diet.
Veg I give daily but don't really count the nutritonal value as part of the daily mix, just small amounts of a good variety to give extra vitamins, minerals, fibre & enrichment. Things like kale are good but really when it comes to veg I think variety is key & only relatively small amounts.
Grass seeds are a natural food for hams but given the choice mine just won't eat it! Whilst trying to keep the mix natural & appropriate I think you have to remember too that our hams are quite far removed from their ancestors & some things are too different to what they've become used too although there are some close options like canary seed (actually a type of large grass seed) which they will eat quite readily.
If you do decide to give it a go I think the idea of beginning with part home made mix part commercial mix is good as your hamsters will need time to adjust to the change & it will also give you a chance to see what's working & what might need changing, that's what I did when I first started making my own mix.