Keep that process lens for low magnification, it may work a little bit better in terms of flatness than the Rodagon for 1:1 ( or that has been my experience).
Also, if you see a 360mm for cheap or free you may want to pick that up. It gives you a little extra room to work in front of the enlarger (dodging, burning etc).
I have a 300 Rodagon also and if you just had one lens, that is a good one to have.
Don't rule out the small formats. I just got a recessed lensboard that will focus a 50mm lens on the wall.
Please share you processing methods when you get it figured out. I started a thread about processing large prints a while back, and I'm probably going to go with 4 30x40 trays and buy paper in a roll but I'm still in the planning stages.