I used a Centech Gv16 harness and it worked out well for me. Everything is labeled so its easy to use. Its a generic kit so you have to use your old toyota plugs to have everything match up. I pulled the old harness out and unwrapped everything and followed the wires along with a wiring diagram.
I am getting ready to go with EZwiring. All of this stuff has been mentioned before on here. Painless is painfull, but then again non are really easy. Painless is just to expensive for my tastes, when i can get the same for less elsewhere.
With the EZ harness it is really not that hard. Make sure that if you go that route that you get the colored harness, it makes things a little easier. Also, EZ (i don't know about the other brands) divides the harness into 4 different "sections:" front of the vehicle, rear, column and dash. It makes things a lot easier.
I also had to really have faith and hook things up exactly as the instructions told me, as EZ Wiring had already figured out how to do certain things. Like the high-beams, for example. There is a wire to hook up on headlight sockets, but I was worried about how the rest was set up, only to find that there was a wire to close the circuit on the column, then I was worried about having an extra wire in there on the dash part for an indicator light, but it was already there. They really have a good product, and their customer service is great.
It always does end up looking like your dash threw up wires though. Just make sure that you WRITE ALL OF YOUR CONNECTIONS DOWN. Even ones that you think you will remember, WRITE THEM IN THE INSTRUCTION BOOK.
Also, remember to put in the headlight fuse as it does not come in the fuse block. It took me a good 45 minutes of being pissed that I had messed something up before I found the fuse in the bag.