Ray,
It's hard to know whether or not the pump is too large. Without having any specifics of the design of your system, my general thought is yes, it's probably too large. The 009 has a relatively steep curve and is generally used for higher head applications.
On the other hand, it depends on the velocity, glycol mix, and temperature your trying to achieve/maintain. Also, you didn't say what size the tubing is. I'm making the assumption it's 1/2". I'm sure some will tell you you can just use ball valves to increase the head. In reality, the higher the head the more energy you'll use; not in BTU/h, but in cost to run the pump(s). The cost to run the pump for 1200 square feet may seem minor, but if you've gone to the trouble/cost of getting this far, you might as well spend a few more bucks and make sure you get the right pump.
A couple of suggestions:
1) Run the design data on your floor, remember that gpm is cumulative but head is not. Since you already have the tubing in your floor, probably the biggest piece of data you need to have is the heat loss. A basic manual J will get you close. If you're somewhat handy with a calculator and you understand the concept of what you're trying to do, you can probably figure out which pump you need in just a few minutes.
2) After you have the data, take a look at Taco's web site, it's excellent. The pump curve you're looking for is readily available.
Best of Luck,
Reflex
