Hi Jennypen,
I have bought a house in the Fort Haven development and im very pleased with it. Gort na Si and Fort Haven are two seperate estates beside each other built by Eirn Construction. There are 8 detached 4 beds and 24 4-bed semis in the first phase. 2 more phases of 4-bed semis are due to start after xmas. I'm not sure if theres any units left in Gort na Si, the estate looks nearly finished.
The village of Coolaney itself is small but has all the essentials - pubs, restaurant, chinese take-away, church, school, community centre etc. Its about 15mins into Sligo town. The population in this area has doubled recently due to the urban renewal tax reliefs. These reliefs are due to end in December but building will be ongoing for the next while. I'm not sure about the rental market, you will have a lot of competition as many new houses have popped up recently and the trend is to buy not rent at the moment. Hope this is of help to you.