Originally Posted by Steve
As long as you are the one moving it, it doesn't need to be much of a rack.
+1. If you're doing all the load in yourself and transporting the stuff in your own vehicle, minimal works just fine. Exposed knobs and faders get damaged easily even on the front seat of your car. For the new lighter heads, a rack bag with shoulder strap is a great option if you are doing all the moving. So protection is the major reason to rack a bass head. If you're gonna hand it to a road crew, you'd better consider some of the shock-mounted stuff (I've never needed this ever).
Since you're not sure what you are going to drive your 610 with, the other reason to get a rack is if you go with separate pre/power amps, or if you think you might add extra "stuff" into a rack case with your amp (e.g. strobe tuner, wireless receiver, power conditioner, etc.). You can also add accessory drawers to the rack enclosures.
Final word: if you don't need everything to look brand new, significant savings can be had by finding used racks. For what they are, rack enclosures are pretty expensive. Currently I have 3 rack-mounted heads that see regular use. One lives at the rehearsal space and is never moved, so no rack. The other two are in SKB-type thermoplastic enclosures with lids on both ends. You can't drop or throw these around, but it allows you to stack and slide them with other gear and have zero fears of shearing off knobs, etc. It also gives you a handle; carrying a rack-mounted head that isn't in a case is a PIA and you're just tempting fate with your exposed knobs.