Personally, I would stick to an OEM Toyota clutch, they last longer and are better quality than most aftermarket clutches. You can pick up the Toyota clutch from the dealer and have another shop do the install to save money. However, brands such as Valeo, ASCO(Aisin), Luk(Aisin), and Daikin/Exedy are also suitable replacements. Supposedly Toyota clutches are made by one or more of those companies anyway, but I would still stick with OEM just for simplicity.
According to the Toyota shop manual, the engine and transmission must be dropped to replace the clutch. However, there may be a way to do it through the wheelwell or some other way so you don't have to drop the engine. The shop you mentioned may be able to do it without having to drop the engine.
Also, clutch "kits" usually come with a few parts in addition to the clutch plate, including the throwout/pilot bearings, alignment tool, and pressure plate. That's why prices may differ, because some places may only sell you a clutch plate and nothing else, although most places only sell kits.
You can also check online, although I would stay away from eBay unless you know exactly what you are getting. Here are a couple places to check:
Don't forget to have the flywheel resurfaced.