looking to build a stir plate and i see people use either a rheostat or the LM317T fan controller. It seems people say the LM317T is better but is it worth the extra cost and hassel? My next question is if the LM317T is worth it www.sritrplates.com has a DIY kit which has everything minus the fan box and magnet for $20 shipped. Price wise it seems like this may be very close to the price to buy the stuff individually. would you agree or is there cheaper places to but the parts?