I've used both the Ignition software solution and the Softing hardware solution and can recommend them both. Expensive, yes (especially the Softing module), but at some point the upfront cost saves the long term cost. Depends what your time (and the customer's downtime) is worth.
I haven't used the AdvancedHMI option, but if cost is king and your time/downtime is cheap, then why not give it a try - you've got nothing to lose.
I haven't used FT Transaction Manager and have not heard much good said about it.
One thing to note - I'm fairly certain you don't actually need a PLC to use the softing module. I mean yes, you'll need the chassis to put it in, and the power supply, but it doesn't require a CPU in the chassis to work. It just needs an ethernet connection to the SQL database and the PLC's you want to grab data from, and it works independently. If you have a PLC in the rack you can use it to do some basic monitoring, but ultimately the SQL module is completely self contained and doesn't know or care if there's a PLC in the rack next to it.