Hi Luiz,
For some of us, our sponsorship is with companies that require certain colors/clothing brands. Last year I was required to wear the Saucony clothing so I would swim with a Speedo suit over my kit and remove it after the swim. Conrad did the same. Candy is sponsored by Speedo so she would wear the same suit for the entire race. Although Speedo is the fastest in the water, the Xterra race is quite long. I appreciate a bit more padding in the shorts on the bike... but in the past I have done the whole race in a swimsuit. This year I am planning to race in Descente trisuits. I like having a proper trishort for riding rather than just a swim bottom. This will end up being whatever you become accustomed to and comfortable with. Keep in mind, cycling shorts will not dry fast enough and you could have chafing if you swim in them and Xterra is kind of a short race with no changerooms for a complete change of clothing

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As for a camelback, again, this is what you are used to. I come from mountainbiking so I am used to exchanging bottles in a feedzone. I usually carry two on my bike and exchange at every feed. If you are used to a camelback you will be guaranteed to get the drink you want throughout the race. I find camelbacks awkward because I never train with them. There is no right or wrong... it is entirely preference.