In the name of keeping things simple and, as you put it "ease of wiring," avoid the DIY Relay circuit and go for a pre-manufactured relay board such as this one:
http://www.ebay.com/itm/New-Style-5V-4- ... 53fc7871f3
Cheaper than you can get all the parts for, and it's already designed and built for you. If you're driving it from the Pi, make sure the one you get has separate VCC and JD-VCC. Normally they're jumpered together, which works fine for the Arduino but since you're using a Pi, the VCC needs to be 3.3v to match your GPIO, and the JD-VCC needs to be 5v to drive the relays.
They'll handle 10 amps at up to 220V AC so your 3.5A 110V lights will be a walk in the park. I built a box with 4 separately switched outlets like the one that you're talking about, and it took longer to strip all the wires than it did to connect them to the screw terminals. Super quick and easy!
As for easy wiring, it's as simple as connecting ground, 3.3v and 5v from the pi, and one signal pin for each relay straight to a GPIO on the pi. Total of 7 control wires for 4 relays, all from the pi. Couldn't get much simpler. I had mine up and running in about 5 minutes, and running scripts that I had written for LEDs in another few minutes. Note that most of these relay boards are active low, so 0 is on and 1 is off. Easy to account for in your scripts, as long as you're aware of the issue.
I'm fairly new to this too, but as far as I know, the only drawbacks of these vs. solid state is the audible click and the inability to do PWM. If you're leaving them on all day, the click shouldn't bother anyone, and if you're using these with $1250 lights, you probably don't want to PWM them anyway, for the sake of longevity. (I'm just assuming that PWM will wear out an LED and/or its power supply faster than leaving it on, but I'm new to this too so I could be mistaken.)