I would do a 2-day variation. Check out page 62 of the Beyond 5/3/1 book if you have it. Your schedule should fit that just fine. Sometimes you might have an extra day of rest, or sometimes you might only have 1 day in between sessions.
When you have two days off in a row, you can train one day and condition the other. Just make sure that with the conditioning that you aren't serving two masters, meaning it will be hard to gain size and increase your conditioning at the same time. Gain some quality size for 12-16 weeks, and then build your conditioning leading into the season.
Jim posted an article by Stan Efferding called "You Don't Grow In The Gym". Read that and apply it for your size-gaining block.