IDE (=pata) and sata makes very little difference, as either connection is far faster than the hard drive itself. Sata have slimmer cables and do some exciting things like hot plug, so are generally preferred.
You can hang two drives off a single IDE/pata cable but only one off a sata cable. However, motherboards tend to support six sata devices and two pata devices.
Finally ssd's are a completely different type of hardware. They are very fast, very good, and very expensive. They are also invariably sata connected.