USACG usually gets rave reviews. I personally have dealt with them and the product quality and customer service were stellar.
I haven't dealt with B Hefner but with their harmony central review feedback I wouldn't go near them.
USACG gives you the choice of a 2 piece maple neck (1/4" maple fret board on maple neck) or a 1 piece maple neck with a skunk stripe for a modest upcharge.Good info.
Do they use 1 piece maple for maple necks?