8ball,
Cool looking ride, lovin' the horns and flap. I agree with the other guys that some bigger tires are in order to fill those 'wheel wells'. Right now, the gap looks a little 'awkward'.
Some 24 x 3s, would be perfect.
There's tons of options, Electra Fatti-Os in white wall or black wall, there's a couple of flame patterned tires out there for a 'racy' look.
Nirve makes the Fat A$$ tire in a blackwall and whitewall too.
Choppers US has several options (I bought Kenda Krazes from them for my bike)
http://www.choppersus.com/store/category/3/16/Tires/page2.html
If you want something with a 'vintage' or 'boardtracker' tread, then Felt Thick Bricks are an option, they come in a whitewall, blackwall or cream. Their Berm Masters are cool if you like a knobby tread, like the ones you're running now.
Here's a cool and relatively inexpensive street tread, I've never seen one installed, but it looks cool.
http://www.monsterscooterparts.com/24-x-3-electric-bicycle-tire-cruiser-street-tread-rear.html
Just found this one too, pretty cheap.
http://lightenupbikes.com/inner-tube-achieva-big-road-hog-24-x-2-5-3-5-schraeder.aspx
Good luck,
Dr. T