If you go the LBS route be sure to ask what you can switch out as a part of your purchase. If you need a different stem to get your bars up for a better riding position they should do that for free.
Likewise, ask about switching out the rear wheel if it appears to be necessary. Velocity an others are certainly great products, but a good tandem wheel will work well and probably be much more economical.
If there is something they won't, or can't, work with you on don't worry about replacing it until it needs to be replaced. Get every mile you can out of any thing that comes stock.