If you're going to do it, do it right. C-notch the frame and do a triangulated 4 link. Gambino Customs makes a C-notch kit specifically designed for '49-'54 Chevrolets. It works & fits beautifully, and also saves lot of unnecessary cutting.
That being said - Don't put the cart ahead of the horse! Your car has some serious wiring issues to address before you even consider air. Has it even been converted to 12V yet? The last thing you want is a full blown car-b-que your first time out. Read my last post. Do ALL the basics before you start customizing. You will save yourself much time, headaches and dollars. If whoever you are talking with doesn't steer you in that direction he should be avoided. There are a lot of hacks out there willing to take your money without consideration for quality work or safety, especially when they know the customer is green and knows nothing about what they are doing.
You said your Dad is an awesome mechanic. What better opportunity to spend some time with him and learn while you are at it? Get yourself home, go through that car completely, do LOTS of research and then maybe pay a reputable shop to install air ride on your car if it is something you and your Dad don't feel comfortable doing. Everybody's gotta start somewhere, and you don't have to be dragging your car on the ground to have fun or be cool, especially when you are learning. It's a process, and it can be a very rewarding one if you take your time and enjoy the ride...