What's your soil PH? Is it loamy, sandy, clay? I am up here in Michigan and I don't plant till early August for my most of my plantings so I think you have plenty of time. For a first timer I would go with rye mixed with turnip, rape, and the Imperial. Rye is easier to establish than oats/wheat but is less attractive. I wouldn't put both oats and wheat, too much grain. As far as the brassica's, after planting for 10 years it's hard to beat Biologic. I used to go the co-op and buy the cheap brassicas, but it doesn't draw the deer as well, and it doesn't grow as well. All "deer plot" manufactores preinnocculate their seed which saves a tonne of work and makes them grow like a champ. I would go bigger if this only food plot/agriculuture on the 120, say 2.5 acres right dead centre. On my little 40 I got 9 acres total. Ed Spinnzola book is a must, grow 'em right is good too.