If there is an Apple store near you, I would strongly suggest you go and spend a few hours (over multiple days), playing with the different laptops offered by Apple. The store will let you play as long as you like, and except for asking if they can help you, then will mostly leave you alone to play.
If a 13" screen is "Good Enough" then it would be a less expensive option.
If you do not need a lot of storage, then a 13" Macbook Air is a very good traveling system, as it is extremely light (my Wife has one). If I didn't need more storage, I would own one.
If you need more storage, then a 13" Macbook Pro can be a good buy. Not as light, but a very good machine.
If you really need to 15" screen then a 15" Macbook Pro is what you should look at. Whether you want to pay extra for the Retina display is up to you. I think the laptop screens are very good even without Retina.
NOTE: If at home you will mostly be sitting at a desk, then a smaller screen and an inexpensive 20" to 24" external 1080p monitor (or even your HDTV via a mini-Display port to HDMI adaptor) can satisfy the larger screen at home, but the smaller more portable device while away from home.
I would consider getting more than the default RAM (8GB or 16GB if you can afford it). The more RAM will allow memory greedy apps to run in years to come as apps and the OS start wanting more RAM.
I would not worry about the CPU speed. Your stated needs to not require a premium price for a faster CPU.
I agree with the others, if a 13" screen is big enough then the MacBook Air will be more than sufficient for your stated needs. Of all my Macs it is the one I use most frequently, due to its portability. Its battery lasts two or three days between charges, in my normal use.
Consider the models offered on Apple's Special Deals page. They are indistinguishable from new, carry exactly the same warranty, and are eligible for exactly the same support as new Macs.
Hi! I would recommend a mid 2012 13" Macbook Pro (non-retina).
It is more than enough for what you've mentioned on your post in regards to your needs.
And yes, it will be more integrated with your iPhone and iPad.
You will not have any problems in regards to the user interface and you will adapt really well to the Operating System. In fact, you'll never want to use PC's again!
Today, Mac's are totally compatible with PC's, so you won't have any issues with that.