Crisps lager malt may be closer to American 2 row malt than Maris Otter. The APA style can range between dry, bitter and hoppy like SNPA to Deschutes Mirror Pond which is softer, malty and gently hopped (I haven't tasted it though). Looking up my notes from Jamil on the Brewing Network on the APA style I have; Aroma-hoppy, floral, citrus, low to high, Flavour-fruity ester, fairly clean, no roast, sweet from malt, clean malt, with a little biscuit; IBU-bold bitterness on the side of bitter, can be done by mostly late additions, 30-40IBU; mouthfeel dry to quite luscious.
So whatever pleases you really. I would always use a few malts for this style so you end up with a bit of body, rather than just use the single base malt. Light crystal is good.
For my next APA which I'll hopefully brew in the next few weeks Im using;
84.5% Maris Otter
4.5% light crystal SRM30
4.5% melanoidin
4.5% Munich I
2% amber
Hops; Northern Brewer, Willamette and Cascade
Good luck :
