I'd go with LSD for the first night in order to get the most out of both drugs. I was planning on taking acid on day 2 at a three-day music festival in April this year and then rolling day 3, but ended up switching the two (roll day 2, trip day 3) impulsively and my trip suffered. I took 1 1/2 tabs of good acid but it felt like a veeery low dose, which I attribute to the fact that almost all my serotonin was probably depleted.
The trip itself was actually extremely positive and great -- I had a beautiful day, was very euphoric and actually felt fine physically and mentally (no exhaustion from rolling the night before). But it wasn't intense at all. So if you intend to trip the night after rolling with no serotonin, I'd suggest upping your LSD dose. It may be different for you, though, so be careful!