One thing I recommend considering is how many staff/volunteers you will have available (consistently) for streaming, and the training/expertise of those volunteers. I mention this, as I have a helper, but realistically, our HoW livestream needs to be a single person operation. So a NDI PTZ camera made a LOT more sense (even if slightly more expensive)
stand for camera? you mean tripod, right? be thoughtful of the ballhead if you are going to have a camera operator adjusting camera while live (so as to not have jerky pan movements)
And people will tolerate poor video much more than poor audio, so consider how you plan to integrate (and sync) audio into live stream
And, assuming your streaming PC is powerful enough to handle the encoding video feed, then do real-time video encoding for the stream, the typical approach would be to have the capture card (USB3?) plugged directly into OBS PC. And beware overloading a USB root hub (to many USB devices plugged into same motherboard USB hub... not always easy to tell which port goes to which hub; or bandwidth overload.. for example camera and USB drive, or USB Ethernet adapter, etc)
And real-time video encoding is demanding work for a PC... don't expect a low-end/low power system to be good at such. Using something low-power, like the Surface Pro or any ultrabook, will require you to get good (most likely) at optimizing OBS to minimize hardware demands of encoding (ie it can be done, but from an expectation standpoint, with an ultrabook you should probably expect to either spend a lot of time playing with settings to get something stable/reliable/watchable, or pay someone to help set up OBS for you, and probably be limited in the features you use in OBS (certainly not Studio Mode, probably not the noise filters/effects, etc). ymmv
I tried to stream a service using a 5yr old gaming laptop, with a GTX GPU with NVENC support, and I failed. With what I know now, I might have got it to work... instead we bought a new 8core/16thread business class desktop PC with Turing NVENC support, and 5yr next business day onsite support. This powerful PC should handle streaming reliably for years. Our budget wasn't so tight (after designated donations) that I had to compromise on the specs. The PC can easily handle live streaming, saving a local recording (at higher resolution), and future video editing if need be. With such a PC, my focus can be on the stream experience, vs worrying about exceeding my PCs capabilities. All depends on budget.