I can't help on the gourds, but I can definitely give some input on the trellis spacing. I have 48 running feet of trellises in my 215 sqft garden, and really get aggressive with the spacings. Some particulars about your bed(s), orientation to sunlight exposure, and a photo would help.

EG

Big gourds like dipper or birdhouse, I plant 6 feet apart. The vines get 15 ft long at least. Maybe with smaller (no actual experience there)gourds you can space them a couple feet apart in one place, closer in another. Sunlight on the leaves will control how many/how big the gourd crop is anyway. Too close they will shade each other. Good luck.