|1) I don't know that anybody makes wireless switches. I suspect you'ld have to buy either another wireless router, or a range extender|
2) No I believe you're right in both cases (ie: no wireless switches and you'd have to use bridge mode to extend the wireless network). For more info on adding a second router, click on my name above and read my "how-to" guide labeled "adding a second router" You'll want to follow the "LAN to LAN" scenario only instead of a cable, you'll be using bridge mode to connect the two. I've never extended a wireless network using bridge mode, so I can't give you any info on doing that. I would just be sure the router you already own, and the one you buy are both capable of connecting in bridge mode as I am sure both ends have to be capable of connecting in bridge mode.
The only real issue I see you having is the signal strength coming from the wireless router in your house. I highly recommend you take a laptop out to your shop and see what you get for signal strength. If it's real low, you need to reconsider how you're going to connect your shop to your house's network.
If it were me, I'd either use point-to-point wireless antenna's to connect the two buildings (google EnGenius and have a look at what they make, I've worked with them and they'd do the job nicely for you) or I'd get two range extenders that mount on the outside of your house/shop. The third alternative would be to run a cable, but that would involve conduit, digging a trench etc etc.
I don't think you'll be able to just run off your wireless router in the house. The distance between locations added to the fact that you'll be passing through no less than two walls tells me you'll probably find the signal strength too weak to work well. So have a look at the other two options.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.