I'm going big as well, and in asking our local brewpub owner/brewer, he said that in his early days he took his IC, put it in a bucket of ice water and ran the beer through the copper tubing, then back into the kettle. After recirculating like this for a bit, he had the kettle down to temp. Seems like a low budget, effective solution. Just have to be sure you pump cleaner through that chiller really well, or just get new copper and make a new one. The plate chillers scare me a little, because I'm afraid trub or hop matter will get stuck in those narrow little plates.