21 works with the stock front end, but 23 requires new trees.
Coastal Moto is a great place to get new wheels- they are my top recommendation. They were awesome to deal with, offered the best price, and had fast delivery. Plus, they are a forum sponsor.
If you are going big, I would check out HHI for trees.
Lastly, I haven't purchased anything from Renegade Wheels, but they are offering "winter build" deals right now. They don't have the prices posted- you have to call and explain what you want.