Hi,
I wouldn't recommend buying in Ballymote - Not a very nice town, it does not have very much in the way of ammenities - Colloney & Ballisodare are very convenient to Sligo but quite expensive
Tubbercurry is a nice town, about a half hour drive to Sligo - new library and county council offices, state of the art seconday school, good health centre, a couple of good supermarkets and a good selection of shops.
Lots of new housing developments being built at the moment - new houses have rural renewal tax relief (think this is being phased out this July). Personally I would avoid developments on the "Sligo Rd" area of the town, a lot of social housing and a lot of houses rented - Charlestown Rd developments seem to me to be the better option - a bit more up market, more owner occupiers.
Also one of the govt depts will be locating in Tubbercurry in the coming months on a temporary basis before permanently moving to Knock Airport, Which is about 15 minute drive from Tubbercurry.
I have lived near Tubbercurry for most of my life and think it is a pretty good town.
Look into it, take a drive around when in the area next