Can you share some examples of high bandwidth 900 radios? In my experience, it’s difficult to get bitrates above ~100kbps on 900 over any meaningful distance.
I work with industrial grade 900MHz radios, and most can do over 1Mbps... with enough SNR, which as I mentioned can be difficult. I would say a typical ~city sized network I've worked on tend to operate in 100-1000kbps modes, with real world throughputs maxing out at more like 300-400 kbps on typically 1-10 mile links.
Manufacturers include FreeWave, GE MDS, XetaWave, 4RF, and others. These are typically ~$1000 radios, so not great for hobbyist use.
In addition to Ubiquiti (already mentioned), Motorola (Cambium) also made some PTP and PTMP radios ("Canopy"?) that were quite popular in the WISP community years ago.
I'd be surprised if you can't easily find both on eBay.