KE Q Class does NOT accru either award miles or qualification miles on any of SkyTeam partners' frequent flyer programs, not just Frequence Plus. Only KE members themselves can earn 70% mileage of such booking class. I learned a good lesson on this without realizing it when buying the KE tickets back in 2003 and lost my Gold Medallion status for 2004 because of KE Q Class.

Anyway, back to the OP's question,..here are my comments.
1. If you can achieve 75K MQMs for sure in 2005, do with DL Skymiles because you will earn 100% mileage bonus on all SkyTeam flights once you reach Gold Medallion at 50K miles) plus Crown Room Club Member (once you reach Platinum at 75K). Especially, if you are still based in the US, DL is a very good option. Plus, if you can reach 1 Million MQMs, you will become LifeTime Medallion (start with Silver).
2. Frequence Plus easily gives you Elite Plus Status once you achieve only 40K miles but you will get only 50% mileage bonus. Over the long run, you do the math for that 50% difference.

Frequence Plus gives you mileage upgrade option (when you fly Economy Y or K fare). But you mentioned you will likely to fly business class only, then upgrade is no longer an issue.

Last but not least, AF website functionality is really way behind comparing to other SkyTeam Partners (e.g. Delta, CO or NW).

Strictly based on my opinion, I will pick the Delta program to get that 100% bonus (at Gold status) plus Crown Room Club Membership along with 6 Upgrade Coupons (on Y, B and M Fare) at Platinum Status.

Regarding Comp Match, contact Delta or go to this thread.

http://www.flyertalk.com/forum/showthread.php?t=9558

You may want to double check but I believe I saw something about Delta matching status from non-SkyTeam airlines. AF does NOT match for sure from what I know. If you can gel Delta to match even up to Gold, you will start enjoy 100% mileage bonus right away.