I am adding a room up stairs in my home, it is about 700sqft. How big of system would I need or should I use a heat pump?

I got a quote on a 1.5 ton system. Is this to much for the room, the will be easy to heat in winter with it being up stairs and I am going to install some thick insulation.

[Edited by macnoak on 03-11-2005 at 05:55 AM]