I installed the signal mirrors about eight months ago, and I just love them.
As far as the fit goes, I purchased the MUTH mirrors, and they are the same shape as the OEM mirror, but without the black trim around the edge.
Now, the installation was more time consuming than difficult. A friend and I had figured that it would take about four hours. Well, after eight hours we had only installed one mirror. Since it was Sunday evening by the time we finished, I had to wait till the following week to finish the other mirror and it also took about eight hours. I'm sure it can be done faster, but we were both complete novices and I'm also very anal and wanted every step done perfectly.
I would suggest that you download the installation manual and study it to see if this is something you want to do. Here is the link:
manual
(Click on "download installation manual")
I'll also be happy to answer any questions.