I have had all the chillers out there just about, from a homemade IC to a chillzilla to a plate chiller. And the homemade IC is best bang for the buck by far. Much, much easier to clean and sanitize (just drop it in the boil for last 20 minutes, hose off before and after each brew). Costs about $40 to build, takes all of 5 minutes to construct.
Yes, in the summer you will not be able to chill below your water temp, and mine is in the 80's here in the deep south. I always have just be certain my fermenter is sanitized properly, run off my wort into fermenter and put in whatever temp controlled fermentation controller I am using and chill down to proper pitching temps next morning. A lot less stress, too, at end of long brew day.