This is a complex question as there are many variables to factor in before the best solution is found for your situation.
To answer your question, I'm going to assume that you are making 5 gallon batches... I started very similar to you, with a 25' 3/8" immersion chiller. With full boils I found the chilling power of this method to be lacking, so I moved to a 50' 1/2" immersion chiller and added a pump to whirlpool. This worked great as I moved up to 10 gallon batches and to some extent up to 15 gallons. Now I have a counterflow and I wish I would have moved to one sooner... I was spending 15 to sometimes 45 minutes to get my temps down with the WIC (depending on ground water temp and sometimes switching to ice) plus the time to pump to the fermenter, where now with the CFC I am done in the time it takes to pump to the fermenter. If you are going to stick with 5 gallon batches, the easiest to use is going to be the WIC assuming you have (or want to have) a pump. However, IMO if you plan on getting bigger in the future then just go with the CFC now and then upgrading size wise won't be a big issue as far as cooling equipment is concerned.
Of course, the biggest factor is cooling is cooling water temp, in PA you probably have pretty cold water in the winter months, which is going to perform well irregardless of which system you go with. However in Louisiana your tap temp is probably much warmer year round so you would need to look at a very efficient system like a CFC or plate or build pre-chillers or pump ice water to use with an IC. Here in Ohio we have pretty cold water in the winter (42F right now) and pretty warm (mid 70s) in the summer, so my chilling strategy changes with the seasons.
Hopefully you see that there is no quick answer (and more importantly no wrong answer) here because you can make any cooling equipment work with the right strategy. Maybe if you give us some more information about your system we could make a more informed recommendation for you.
Biggest questions are finished batch size, boil kettle max volume, do you want to use a pump/already have a pump, chilling water temp, do you filter hops/trub, do you have a spare vessel for ice water/pre-chilling, how much are you willing to spend?