I can actually help with both of those. Alternative grill choices that are available now:
Strut - I am a distributor for them. I have a thread elsewhere on the forums that has a number of pictures of their products. They also have a few options not pictured as well as custom painting and such. https://www.fiskerbuzz.com/forums/27-...-products.html
"Surf" Grill - This grill was made completely by hand based on pictures of the Karma 'Surf'. 100% fiberglass with a manufacturers warranty for life that guarantees no cracking at all. In stock. http://fixthekarma.com/?product=custom-karma-surf-grill
"Paranoia" Grill - A grill patterned after the one used in the movie Paranoia with Harrison Ford. I should have this ready for pre-order quite soon. For pictures PM me, I have a few on my phone. Here's one to start: https://www.fiskerbuzz.com/forums/27-...oia-grill.html
For the wheels, I have a meeting coming up with a major wheel manufacturer out here in California. The owner of the company has a Karma that I've done service on and he says he's had 24" wheels on the car already. I'll be happy to get you more information on tire sizes and pictures of what rims will fit.