The Academy/Minicraft H-60 models are the best in the 1/48 market. They have quite a few versions too. The best kit to start with would be their MH-60G since it comes with the square, folding rear stabilator and lots of extra parts that will be usefull in building an HH-60J. Also, Italeri has an SH-60B that could be converted too. It is already in the Navy configuration so you would have to do less to it than an Academy MH-60G. It is less detailed that the Academy/Minicraft one though.
If you didn't already know, Cobra Company has a 1/48 HH-60J nose conversion for the Academy kit. They also do a full HH-60J conversion for the Italeri SH-60B kit too.
Good luck and keep us posted.
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