i would say hosho. although when you first start out in the junyo line, you can reach new CVs at lower levels, but in the long run the remods along the hosho line beat out any base model along the junyo, although they do make you spend more money. i made the mistake of not taking hosho. junyo may be better than hosho/ryujo, but in my opinion that's the only one in that line that is.
take note for later use, whether in CV or BB. it is best to have 2 BOs so you can take two different lines and up your FP/Bs faster. if you don't want to switch between BOs all the time, power grind one; class it as a certain nation sailor, but wait til it reaches at least CV1/BB1 level and then make it a bridge operator. it may be too late, but i would take both routes, but ONLY if you have the credits to do so. if not then just go the hosho line. and if you hate all the CVs in any line, get a PCV :)