The Eclipse and Talon are exactly the same vehicle. If you remove the rear bumper and taillights, and remove the front bumper and headlights, they are visually identicle. The Talon has taillights that are wired slightly differently than the Eclipse, but everybody and their pet monkey converts the Talon to an Eclipse (which is retarded since the rear of the Talon is 25X sexier than the Eclipse, but in the car world, everybody's sheep and does what the other guy's doing). This is true for cars from 95-99 (95-98 for Talons). The 95-96 headlights are only compatible with the 95-96 front bumper (Eclipse), and the 97-99 headlights are only compatible with the '97-99 front bumper (Eclipse). The '95-98 Talon Headlights are exactly the same as the '95-96 Eclipse headlights. To do a front end conversion or rear end conversion, all you need is all the parts from the same year range. I.E. if you're converting a '95-98 Talon to '97-99 Eclipse, all you need is the '97-99 Eclipse bumper and headlights, it's a bolt-on. Same goes for the taillights or sideskirts. The Talon taillight wiring harness is actually the correct harness if you want to use European Eclipse taillights on your car (just a thought, they're different than USDM taillights).
Also, the 98-99 Eclipse was available with an all black leather interior which was not available any other years or in Talons at all.
The only difference between the cars is visual. Mechanically they are identicle, any performance part that will fit an Eclipse will fit the same model Talon. I actually really wanted a Talon when I got my Eclipse (since I'll be converting the rear end to a Talon anyway), but this Eclipse had everything I wanted. But, the Eclipse costs more for the vehicle (remember that thing I said about sheep... it drives the price up for the more popular car), plus the Eclipse costs $200 more per year for insurance (I have a perfect driving record).
You can find an in depth answer to every question you have at either of these two websites:
Now, everybody and their purple monkey has asked the questions you're going to ask. So, your question has been asked and answered exactly 1,345,178,237 times, do a search on one of the websites and all will be answered.
Welcome to the DSM community