I'd honestly consider wet Okole's before I did that... they would probably be much cheaper, make your seats more comfortable, and greatly improve the look of your interior. http://www.wetokole.com Very durable, wash right on seat, waterproof... I bought some for my dad's 2000 tacoma because his seats got worn out and he loves them.
No, they do not require professional installation. My dad and I installed them on his tacoma over the course of a lazy afternoon. And, on my crew cab tacoma, we installed two rows in about 3 hours... making them fit perfectly. We did our installs with the seats inside the vehicle. There was a recent tacoma group buy, and out of the 100+ people, no one has been unable to install them.
If you run into any problems, there is an wet okole installation thread in the 05+ tacoma forum. I would recommend ordering swatches before hand to see what color you would like to get.