I don't particularly care for the spit forks on the Weber and other brands, but that's just me. I do have the 8" EZ-Que cradle and would recommend it in a heartbeat! They have been out of stock for months and hopefully they get back on track because it is quality unit.
But if you have the forks truss the birds and they keep their shape on the spit.
Lowes had the Char-Broil rotisserie basket on sale for @ $8 and this thing is pretty cool too!
I've been really getting into spinnin' meats, and the flavors off the drum and Cajun Bandit (direct) are producing moist and tender cuts and I don't get the real crispy burnt skin I might get if I use teriyaki or sugary marinades. But even cooking indirect on the kettle is superior to most grilling.