They are LSI2008 cards with different functionality enabled. There are tons of options where some support RAID5/6 while other just support RAID 1/0/10. Some require a license to enable more functionality. Most people around here just use them as HBAs though. With the IBM cards you can flash the LSI IT firmware to enable passthrough mode and with the Dell H200/310 you can flash the Dell 6Gbps HBA firmware. Or if you want to run hardware RAID1/0/10 then you can just run the latest firmware from their respective product pages. They are awesome cards for SSD in RAID0. About as fast as it gets. Even if you pick up a card that supports RAID5/6 I wouldn't use it for that purpose. RAID5/6 should be done on a card with onboard cache. There are tons of high end 3Gbps RAID cards on eBay for under $100 if you want to pick up a card for RAID5/6.
Sorry... rambling a bit off topic there... I typically pick up whichever ones I can find on eBay the cheapest. I have alerts setup on eBay and I get an email every time a H200/H310 gets posted for less than $75 and I'll usually pick it up right away. One doesn't have any advantage over the other if you're flashing it to a HBA. If you want hardware RAID functionality then I can go further into the differences.