I found this webpage that explains a few things about fresnel lenses and lenses in general. The notable thing I took from that is that the recommended F number is between 0.5 and 1.5. From my understanding, the "diameter" of the lens would be the longest edge-to-edge length of a square/rectangular lens, which for a 52mm square image, is about 73.5mm. With a required focal length of 30mm, the F number is 0.41 if I'm calculating correctly. The smaller the F number, the smaller the "airy disk" for a given wavelength, which is a good thing. From what I can understand, the issues for using F numbers smaller than 0.5 don't apply to this application. Another thing is that the limit of spherical lenses is f/0.5 allegedly, meaning that the fresnel I plan to use is aspheric by nature.

I'm thinking of buying 1 set of lenses for a test, conviniently because this off-the-shelf fresnel exists:

I'd also be getting some 5mm right angled prisms and maybe a 9 or 10mm beamsplitter cube. I'd like to validate the optical path though some specialist software first, because it's still kind of pricey for a test run:

I dunno... a single test set is almost half the cost of the full order, partially because I get free shipping if I order a certain amount.