If you only want to cruise around you should get a Stereo Vinyl Cruiser and some Bones Red bearings from amazon.com. All together it would be about $80 at the max.
http://tinyurl.com/ak592kp Stereo Vinyl Cruiser
http://tinyurl.com/ajlqkwr Bones Red bearings
Personally, I'd recommend you just buy a regular skateboard. Though it would cost more, it would be more fun to learn how to do tricks and you can also ride around perfectly fine on a regular board.
http://tinyurl.com/ao9asoz Blank pro deck
http://tinyurl.com/av34dux Very pro trucks
http://tinyurl.com/ay6xnwj Pro wheels
http://tinyurl.com/ajlqkwr Bones Red bearings
http://tinyurl.com/ax56lrm Good hardware
Again, I'd strongly recommend the regular skateboard. And I wouldn't recommend the longboard at all.