1. Patched if it's near the center. if it's within 1" from the sidewall or on the sidewall, get new tires
2. You can get tires online (www.edgeracing) or go to discount tires. Anywhere that sells tire.
3. If you have money for good wheels (not cheapos heavy ass ebay wheels), then go ahead. Other wise, replacing 2 tires will be more cost efficient. $400 vs $4000.
4. Wrong forum.
5. PM me if you want hook ups on wheels and/or tires.