Roaches make an awful feeder when it comes to delivery lol
Everything else about them is great, but you cant just release them in an enclosure.
They will only hide, and stay hidden until nite.
You can put them in a cup, or bin, and feed them that way, but they will be very still, which wont draw the chams attention. Some have had success with putting a cricket in with the roaches. The cricket walks all over the roaches, causing them to move about. The cham may just eat the cricket though, and thats it.
I have found the best way to feed them, is either by hand, or placing them on the screen, near the cham. They will start to scurry off to hide, ideally in an upwards direction, and the cham will can pick them off.
Sounds like you got a good deal on them!
I am unsure about hissers.