The correct answer is that you want a true LSI HBA.
Most RAID cards offer some sort of "HBA" mode, but these range from "we create virtual devices that cover drives" to "we pass through requests to the drives". The main problem is that the RAID card device driver is still used, and many of these are suboptimal, are buggy, or are less than perfect. The secondary problem is that you're still dependent on the RAID card firmware surviving, and ZFS is known to place a huge workload on it - a RAID card torture test. Even for cards where you can manage to get proper SMART support, this really isn't worth the risk.
The LSI HBA isn't something radical. It's nothing more than a low-end RAID card with a processor. It's just that the FreeBSD driver is known to be non-problematic, and it's known that the IT firmware is known to be non-problematic --- to the tune of billions of aggregate hours of runtime across the installed base.
I have absolutely no doubt that there could be other stable device driver/card combos out there, but it is also known that there are other dodgy combos out there, and so if you don't want to be having to be a guinea pig and you just want your data stored without drama, it's LSI HBA all the way.