I love my Sports, drop is 100x better then stock and is definitely noticeable. Plus, with careful driving I have not scraped my LT's in Chicago. I am removing my LT's soon and I think I am going to drop it a tad bit more to have it sit perfectly - gonna remove the front isolators and get some MM adjustable LCA's to drop the rear about half an inch (as well as help fit the 315's I have sitting in my room).
My Car:
Good shot of a Cobra with STOCK suspension and my car next to it with my current suspension setup - you can see the big difference up front between the two:
the sports are nice.
and you will notice the drop, that's without a doubt.
but are you one of those people who will say afterwards:
"ah, you know... I should have gone lower"
To answer your real question....yes you can install them yourself, its very straightforward and can be done in less than three hours (depending on how much beer is handy) You can do a thread search for step by step install questions.