depending on where you live, a pool may actually see more use than a swing set. in georgia, pools are pretty much a viable option right into late september and even october! also, how long are the children going to be interested in swings for - maybe ten years if your lucky! on the other hand, a pool would benefit the whole family for years to come - and just think of the pool parties!
however, pool safety is a huge must! deaths from drowning most often when the child has been seen within the last two minutes! it doesn't take long for a little one to wander into the water. a fence around the pool - at least until both children are avid swimmers is important. as is keeping toys out of the water so there are less incentives to go in. swimming lessons are a must! even at two years of age, your child can learn water safety and keeping calm if he does fall in. the two month old probably won't be walking for a while so he can wait :)
***edit: and just for comparison, swingsets result in thousands of injuries, if not more- they aren't exactly the "safe" option, only "safer". in fact, based off of numbers, i would bet swings account for a higher total number of injuries. either way, you will have to watch your kids constantly, so why not get the house you really want?