You can purchase the Barebones Induction Heater module from Pipes at http://fuckcombustion.com, send him a message with your order request and he will send you a Paypal invoice.
The barebones IH module fits fairly snug in my prototype print even when in use it does not drop or slide from position. The prototypes were printed with 10% infill, I would probably increase shells to 3 or more than add more infill. It takes about 7hr to print. Print with support touching buildplate if you want the top to be smooth or print it upsidedown if you want to save on material.