Yep, can’t fit 8” rims, will foul guards along with rubbing on body and make the deck angle sit up. No room for bigger rims on front either, next size up catches and you can’t turn the steering; so even if you cut and shut the guards you’re going to have additional problems.
There’s an absolutely cornucopia of “ATV” tyres available from sizes for kids mini-atvs and up. There’s a few sellers of gear who advertise a range of spare bits and pieces along with what seems like a huge range of tyres. I have a couple of catalogs for atv spares to suit the one we use and the options for tyres go on page after page. These are just the “genuine” spare parts catalogs for my machine. The aftermarket options are an order of magnitude more massive.
If you call around mower shops and have no luck on “ag” tyres for your Greenie then I’d be trying the atv tyre route. I buy mine from the tractor dealer when I need them so that’s probably no use to you. However, there are local dealers for these things in most towns and quite a few internet sellers.
