Hi, i have the academy P-40C in a 1/48 scale, is a good model but i like the monogram P-40B the most (1/48 also), the academy model is a litlle feature less, is a very simple model without much detail, the monogram model is more detailed, is a bit better, i dont know about 1/72 models neither AML nor KP Yak1, hope this helps.
Thanks!
My Best Regards
Hector Reymundo