Wireshark is the best FOSS for packet inspection, but you’ll have to test the efficacy of your solution on enterprise hardware directly if you’d like to know which ones it works for. You can virtualize many of these FW on Azure cloud for an hour and it won’t cost much, but you’d need to know what you’re doing.
You don’t need to buy server hardware, although it is nice. Depending on where you live you might be able to buy some decent second hand server hardware.
If it was me, I would buy new desktop hardware. Here is a fairly decent server that will do almost anything: Go for around 16 or 24 core CPU with high Ghz per core. 64GB or 128GB DDR5 RAM. Your most important factor will be storage speed. Go with NVMe drives. You have some choices here. JBOD: One or more independent M.2 key drives. Software RAID: Use your CPU to manage the RAID configuration. Hardware RAID: Use a RAID controller HBA card to manage the RAID (faster but single point of failure). Use RAID 1 for data protection (can lose one drive and still have all your data), RAID 0 (double the speed of your drives), RAID 10 (best of both but needs double the drives). Choose a motherboard that suits your choices.
Things to take into account: If you go with a RAID controller card, make sure that the PCIe lanes it uses can take the full speed of your RAID configuration or you might be bottlenecked there. Choosing an Intel or AMD CPU doesn’t make much difference. If you are not good with linux distros and don’t want a learning curve, stick with something like Ubuntu LTS 22.04 server. You most likely won’t need any graphics card, but it depends what you want to do.
You can run a minecraft server on an old laptop, so these specs might be overkill, I just put what I would get and it will do almost anything you want to do with it. An 8 core CPU, 16GB RAM, with 1 NVMe drive will also be capable of all your described needs just fine.
That class of storage is very expensive to get your data back. Buying a drive will be cheaper.