I've used the Alpha's and the CTS's and there are pros and cons to both.
The Alpha's have the vertically configured switch like in the diagram above, the switch lugs are in close quarters but they're not too bad to work on. The switch internals can over heat and seize up if you get heavy handed with the iron... The actual pot part of the unit is actually a mini-pot which isn't my preference all else being equal. They are tall, but I haven't had many fitment issues. I've used a lot of these.
http://www.stewmac.com/Pickups_and_Electronics/Components_and_Parts/Potentiometers/Alpha_Push-pull_Pots.html
I've only just recently tried a couple of the CTS push/pulls. They are certainly a different animal. They are a full size pot, which is great. I personally find them a bit stiff to rotate. I find most CTS pots a bit stiff to rotate, so take that with a grain of salt. The switch is robust and feels great. The switch terminal configuration leaves a lot to be desired in my opinion though. You get little eyelets instead of lugs and they are right under the actual pot lugs, it gets pretty tight in a hurry if you're using all of them. You have to be careful feeding the wire through the eyelets lest ye contact the grounded pot case.
http://www.stewmac.com/Pickups_and_Electronics/Components_and_Parts/Potentiometers/CTS_Push_pull_Pots_DPDT.html
So, long story short, either one will work for you just fine. Bourns also has push/pulls, but I've never tried one. I'd like to, as I really like their standard pots.