I used 12v outdoor lighting myself. I drilled through 11" of concrete and ran the wire through it into the basement where I put the outlets AND the transformers. I mounted the transformers on the wall at the top of the basement steps so if I want to manually turn the lights on, I can, or if I need to change from Standard Time to Daylight Savings Time, I can. (I put a 1" hole in the floor near the corner of the top, basement step to feed the 2 'leads' through to the outlets under the steps.)
Also, I soldered my connections. If there's a lot of freezing and thawing going on, the buried wires can be 'separated' from each other and the lights won't work. Then, you'll have to dig up your connections and re-do them. So, I cut off the connectors, 'bared' the wires, and soldered. (If you do this, make sure you SPLIT the main wire a few inches IN THE MIDDLE (hot & ground), bare 1 at one place, and bare the other in a DIFFERENT place. In other words, DON'T bare the 2 leads right next to each other. If you do, you'll short them out.) Then, after I soldered them, I cauled over them with Tub & Tile Caulk, then I wrapped them in some Shrink Tubing. It's been 5 years and they all still work. I live in SE PA too.
Again, if you go with 12v, make sure you get the right size transformer! If you under-size it, your lights will age very quickly. I bought Kitchler Lights and they gave me a booklet to calculate the right size transformer. If you need more info, e-mail me directly.