The iMac is supposed to get hot the aluminium is a natural heat dissipator and it's not a glorified laptop either. To OP I'd stick with the Pro if I were you.
considering that it uses laptop components stick on the back of a big screen, i would say its a glorified laptop.
yes its supposed to get hot but when it does it sounds like a jumbo jet taking off 2 feet in front of your face. If you can live with that during intensive work then good for you.