I love TECs/peltiers!
With out them my lasers would only be a fraction of the power, and my computer CPUs couldnt be over clocked nearly as hard.
Ok, here's what you need to know, peltiers/TECs can not just make heat dissapear, in fact they actaully increase total heat. So why are they awsome coolers you ask? Because they are like pumps for heat, they suck heat out of one side of them and move it to the other side. Now, this other side needs to be setup for dissapateing heat in large quanities, or it will quickly reach the max temp difference (called the Delta T) of the device, and no further cooling can occur. It also often causes damage to the device.
If you want powerful TEC cooling, this is the unit that I use.
http://www.dangerdenstore.com/product.php?productid=85
That unit does the same amount of work as a 1/3hp chiller!!! And you can use as many as you want! Totally reliable, effectively infinate lifespan, power efficient, tiny, silent, and cheap cheap!
Now, the down side... All the pre-made fixtures for useing peltiers to cool fluid that I know of use copper, silver, aluminum, or so other metal as the base plates to sandwich the peltier. The hot side can just use a large CPU heat sink and cooling fan. Something like this would be fine.
http://www.ewiz.com/detail.php?p=FAN-A1671&c=pw
So, long story short, with peltiers/TECs, and a little DIY spirit, you can easily make say a 1hp chiller thats totally silent, tiny, 100year+ lifespan, and all for under $150.
If you just need to drop a 55gal though, a single 1/3hp unit, a single heat sink/fan setup, and a single waterblock (that doesnt use metal, likely have to build you own) would be more than adquate, and the cost should be below the $70 area for all the parts needed.