If I were making a Trumpet Girl, I'd totally go with Purple Tux Gonzo's body as the base, as it will require the least work.
And, call me crazy, but I think Marvin Suggs has the right head shape, and could also donate the hands. You'd need to tweak the head sculpt to remove the facial hair and add the wig, but otherwise it's just a matter of swapping out parts and painting the 'skin'.
Then go to Hobby Lobby and buy their Toob of Musical Instruments.
It will give you the option of a trumpet or a trombone, and if you print out their online coupon for the week, it's less than $6 for eight instruments.
Alex