Congrats on the jump into AG - just remember that each persons system will be slightly different so if things go a little pear shaped on the day, just learn from what you have done and rectify it on your next brew. Took me a good 4 brew or so before I really knew the capacity/efficiency/etc of my system. In the end, as long as you make beer, you're onto a winner!
As for the recipe, I would either look at halving the crystal, or mashing more around the 66'C mark. Might end up quite sweet otherwise. Apart from that, good luck and make sure you report back on how it all goes.