I hesitate to make specific comments without knowing soil types and topography of somebody many miles away, for instance the Soil-Max advertising uses figures that are way way off for me- like 50% off.   "Here" that's enough tractor for laterals at 30-36" target depth and not much more.   However, you don't necessarily need to spend extra getting started out to handle bigger/deeper.   If you need big mains installed, contractors with wheel machines aren't doing much in August- they'll probably make you a good deal to come and trench through some standing crop.  Worth sacrificing a few beans, and when you come back to a main already installed you'll have a dry place to work.

Laser has worked for a long time and can be done cheap, but productivity is vastly better with modern GPS control.   Especially if you're working with a limited crew of two or three people.    I'm on Ag Leader RTK with Intellislope, it's got a few limitations compared to some other programs but it's very friendly and intuitive to use.  

You have enough pieces of the puzzle already to make adding the plow very economical.    Fixing trouble spots on your yield maps is satisfying and addictive.   Way better use of your time than trying to rent more acres.   I've put more than 400,000 feet through this now.