In my own experience, I like vRanger Pro far, far, far, so very far, better than the veeam product... I've had ok experiences with the Acronis B&R 10 software (current release)... I've also had good results with the vDR product... It all depends on what you're looking to backup/do...
I would advise that you use full SQL for the database if you get/install vCenter... Especially if you opt for either the vRanger Pro or vDR products (not even going to touch veeam... I just threw up a little in my mouth just thinking about it)...
You also need to plan where you're going to place these backups, how long you plan to keep each one, how many differentials you plan on having/keeping before a new (full) backup is created, etc... Personally, I would opt to have your VM's on a SAN (even if it's a sub $3k chassis with SAS drives in it) and another SAN for the backups to go to. You could use cheaper SATA spindles in the backup SAN, making sure you have enough space to contain what you need...
I really WOULD opt to get a license for vCenter Server... Especially since you're already planning on adding another host server. Better to get it now, with everything integrated from the start, then have to rebuild your backup scheme later when you do go that route. You gain a LOT of administration capabilities with vCenter in the mix, even with just one, or even two hosts...
VMware VCP4
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