We drove last year from Spain to Iran and I just agree 100% with all Matt just said.

You've got a quick car, so rush towards Turkey and start your trip there. We went via Italy, Slovenia, Serbia, Croatia and Bulgaria because we came from Southern Europe, so not that good for you. Just try to see some sights on the way in the places you sleep, so the kids do not get so bored.

Turkey is just beautiful, as Turks are. Even if it sounds too typical, don't miss Capadocia and Pamukkale (and Istambul!), and maybe get lost in smaller towns. We enjoyed a lot Zile, where had loooong chats every night having tea with a really nice group. The Black sea coast ist not that special. Trabzon is nice, though. Driving, pay attention to the road. I was told they are converting two ways road in highways (adding a parallel two way road) to avoid Turks to overtake like crazy. However, you can handle it. (we spent almost a month)

But if you feel like, go via Georgia and visit Vardzia, which is really amazing, as well as churches and monasteries. Just one thing: avoid the road in Adjara, southern Georgia. After Khulo is just terrible, you would trash your car (we struggled in a very lightly loaded Renault 5, pure farmer's car). In general, the rest of the roads in your (whole) trip are very well, except for some big potholes in Georgia, I'd say. No visa in Ge.

Armenia, if you get that route has wonderful monasteries. And visa available at the border, as garanteed struggled with stupid border officials. You will have to pay some fees for the car, but no CdP (ecological tax, etc).

Iran, what can I say: focus on it and stay as long as your visa allows you to (we asked for 2 months). Iranians are just great, generous, kind, polite and friendly people. Very safe. Roads are great. Driving is just mad, but you get used to it. It will be very hot, especially in the south and check Ramadan dates, you'll get it during your trip, but no worries being a traveller and non muslim.

Apply for Iranian visa in advance. It tooks us two months and lots of phone calls. Just be absolutely transparent. Ah, I read here some people saying they didn't need a CdP in Iran, but still do not know how they managed, so check that thoroughly.

Hotels... I find difficult to book in advance. Just bring camping gear for Turkey and even in Iran (they just love tents and pic-nics). We foreigners are not allowed, but if you find no accomodation, just pitch your tent close to others -they are everywhere!- and will have great fun with your neighbours. Being not so touristy, not very good accomodation infrastructure. Visits? Yadz, Esfahan, Shiraz (Persepolis), Aras River Valley (coming from Armenia, wow!). So much to see!

Two months is not too long, but you will have great fun! And the kids as well. Ah, your wife will suffer a little more the heat with the scarf. You will forget about shorts as well.