The Wista is a nice little 5x4 field camera, which means it is primarily designed to be taken out and about, with the compromises that entails. For leaning on, and for 99% of any pictures you are likely to take these compromises are fine.
The lens equates to a roughly normal FOV, so 50ish on a 35mm camera. The aperture is nice and wide so focussing shouldn't be too hard.
The things to check on the camera are that all the fasteners tighten nicely by hand and don't require excessive force to move, that the focussing bed moves smoothly, and when everything is tightened down that there is no play in any of the joints.
I would also take a powerful torch and use it to check the bellows for pinholes. The occasional very small pinhole isn't too bad, but on something being described as excellent condition I'd want none, or certainly only a couple
As with all things, check the shutter speeds sound accurate and that the aperture stops down nicely and is in good condition. Check the lens for marks, but if it is a Schneider lens there may be small silvery marks which appear inside the lens. This is a common problem (known as Schneideritis) and doesn't really affect the lens too much, but again could be a bargaining point
You will also need film holders (commonly misnamed as dark slides), a reasonably heavy tripod if you don't already, a loupe will be useful, and some film (and a changing bag to load and unload the film)
If you do make the jump to 5x4 prepare for an enjoyable learning curve, and going out for the day with the reasonable expectation of only taking a couple of shots. It's hugely rewarding though
