A lighter, faster bike (faster in the sense that the bike is lighter, more aerodynamic, etc. ) will be... well... faster. But you don't need to break the bank to get into that arena. You can put yourself on a 19-21 lb road geometry prett cheap.
As far as training goes - the question is "How fast do you want to get there?"
If it's just about completing the distance, I would spend the next 6 months only worrying about time in the saddle. Fitness will come along and so will some speed, but the real goal is to increase your aerobic endurance and day to day recovery ability. Increasing your weekly mileage by about 10% is considered the "standard" from week to week. You might increase it less at the beginning, or more - depending on how fit you are now. The slow increase will help you learn hydration/nutrition requirements along the way.
Once you're comfortable doing 2 days back to back @ about 60 miles, then I would start working on intensity to work specific areas of your cycling fitness which will both improve speed and continue to develop your overall aerobic fitness.
I'm also assuming that you intend to ride the distance without a rest day, which means you need to build up to riding 4 days in a row. This will also teach you quite a bit about rest/recovery. A lot of the folks I know that don't ride successive days or say they "can't" is because they don't know how to sleep/eat/rest properly between hard days.
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