Building a bike is a great way to go if you: (a) need a custom frame, (b) have an assortment of components on hand, or (c) have a plan for the perfect bike and don’t mind incurring the much higher cost of spec’ing your own build. Otherwise, it’s preferable to just make a few desirable upgrades to an off-the-peg bike.

Also, you should really specify what your intended use is. Road bikes come in many forms, including touring bikes, recreational riders, and racers.

Giro vs Bell vs others. Choice depends on comfort first; not everyone has a head that will fit well in a Giro. Buy whichever fits your head and your wallet. Helmets need periodic replacement, so it’s not as though you’ll be stuck with the same helmet for years.

Saddles are the same way. Don’t lay out $150 for a saddle unless you KNOW it will fit you OR the retailer will allow you to exchange for another saddle once you discover you’ll never be comfortable in the first choice. Fizik are popular,,,and so are Selle Italia and Specialized.

Bar tape is a consumable. No one really cares. Just replace before it looks horrible. Fizik and Deda are worth trying. I don’t think Cinelli has anything over the cheaper store-branded bar tape.

It’s Velox rim tape. For rim tape, you basically have a choice of cloth or plastic. Cloth protects the tube just fine. Velox is cloth. Some people use plugs over the spoke openings; the advantage is that you don’t have to rip the rim tape off should you need to replace a spoke.

Gatorskins don’t go on Zipp wheels. Apples and Broccoli.

Thompson seatposts. If you want aluminum, Thompson makes a good, light product. If you want carbon, you’ll have to go elsewhere.