This is a great question. If I were getting that set, I'd definitely want the shallower front wheel to have. I often swap to a shallower front wheel, and I've always wished that it were easier to do this with ENVE wheels. I myself have older ENVE 6.7's and new ENVE 3.4's, and running the "3.7" configuration works well when it's windy.

I've also had the older 8.9's, and running the "3.9" combination (front from the 3.4 and rear from the 8.9) worked great in most conditions. Rarely is the rear wheel a problem in windy conditions, while having the shallower front wheel is quite reassuring and easier to handle. It is great to know that the front-rear combo you describe is available – I will check it out when I eventually get nicer wheels for disc-brakes road!

If it might be used on a tt bike, I'd probably just go with the 65 set. A 60mm front wheel is pretty standard, shouldn't cause a whole lot of handling issues, and a 45 is shallower than I'd want. You could then either save up for a disc to pair with the front 65 or figure out some sort of disc cover for the rear and then you'd really be set.

Of the two, I’d go with the 5.6 wheels. You already sprung for a Parlee. What’s another few $100 in the grand scheme. The 5.6 will give you more options for tires. With the Foundation wheels you can’t run GP5K TL.

If you expand your options and run tubes, I’d go with the new Roval Rapides. I’ve had 5.6, 404 NSW, 808 NWS, 858 NSW and many others. The Rovals handle the best and are a very aero do it all wheel set.