Have you looked at these?
http://www.ebay.co.uk/itm/TAMIYA-580...item337d579f46
http://www.ebay.co.uk/itm/TAMIYA-580...item43b51e8ae9
The only thing I would say to going brushless is that the transmission will suffer especially as the tamiya models tend to not have a slipper. I don't know whether one was available as a hop up but if it was I would suggest getting one.