Right off, I would not recommend putting a two year old in a stroller where he only stands. It takes a ton of strength and concentration to stand long distances. The youngest you should consider doing this is three years old.
I do think the Phil and Ted's is a good option for you, but if you do not like that, why not try a Valco Trimode Runabout with a toddler seat. You can put your toddler in the stroller when you need to and if you only have one kid, you take it off and it's a single stroller.
This option is very compact and much smaller then a Phil and Ted's
If you are interested in seeing both these option, you can go to www.letsgostrolling.com.
They have a showroom in Downtown Oakland. Also, I know they are having a sidewalk sale in the 23rd of August. 10-4 pm.
Good Luck