The Tap: https://www.tapwithus.com/
I've got one of these and I like it. It is pricey at around $180us including tax and shipping. And it has a learning curve: you need to learn how to type. Again.
The good news is that it's surprisingly easy to learn. The bad is that it's surprisingly hard to master!
It won't allow you to type in the SteamVR overlay, but anything that accepts bluetooth keyboard inputs work fine.
-Finding a surface to type on while standing can be interesting! I use a small cutting board in my pocket.
-The mouse feature is almost useless if you are using it standing, as your clothes will trigger many false inputs.
-Your Bluetooth dongle MUST be of the newer variety: newer than 4.0 if you can find it. I've got two recommendations, depending on your budget. If you go for the cheaper option, then you will need to plug the dongle into the usb port on your headset to stay in range.
I'll have to dig for the link for the cheap one, but the expensive one is: https://aircable.co/shop/product/acc1615-aircable-host-xr5-85