Mounting Ikea Effektiv Cabinet on drywall with metal studs

Another question for those with more experience than me. I have done several searches with google and called my local Ikea store but I'm still not happy about the "best" method I have found so far to mount Ikea Effektiv wall cabinets.
The only information I've found on the web about mounting these cabinets comes from: http://melissa-knits.blogspot.com/2007/04/efffective-effektiv.html
Ms Morgan-Oakes hung her cabinets by putting one Ikea mounting bracket over a stud, and then used a 2inch L bracket inside the top of the cabinet at the next stud to tie the top of the cabinet to the wall. She didn't use the remaining Ikea mounting bracket.
I'm a bit concerned that if I put heavy items in these cabinets that with metal studs they will pull out of the wall.
The cabinets are for office use and have flush backs, so no room for 2x4s or kitchen cabinet rails. Here is the Ikea page on the cabinets: http://www.ikea.com/ca/en/catalog/products/30050140 Weight: 13.9 kg (30.6 lb) Width: 85 cm (33.5 in) Depth: 36 cm (14.2in) Height: 42 cm (16.5in)
As you can see there are two beige plastic covers that go over two L- brackets that Ikea supplies to support the cabinet once you choose appropriate mounting hardware. The holes in the backets align with holes in the backs of the cabinets and are 29.5 inches apart laterally. I have metal studs in my drywalls which are 16 inches on center. I have two of these cabinets and I'd like to hang them side by side which means that only one of the mounting brackets would line up with a wall stud.
I've been to Home Depot and considered the following options: A. follow the L-bracket into studs approach B. use large shelf supports under the cabinets to support them C. use a 1x2 under the cabinets screwed into the studs to support them, and L-brackets to tie them back
B would be ugly, I'm not ready to trust A yet, and C might the best option.
In addition to requesting additional ideas (other than 2x4s, kitchen cabinet rails, cables, chains, a plywood backer, a metal plate backer -- though if that's the best way then so be it) I'd also appreciate information about what size metal drywall screws to use (length and diameter), and what size toggle bolts to use for the Ikea brackets that don't line up with the studs.
Thanks for your attention, -Jason
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Remove a strip of sheetrock horizontally about 3" wide and spanning several studs and replace it with a strip of plywood or furring the same thickness as the removed sheetrock, screw that to the studs and the cabinets to the strip. All will be concealed behind the cabinets. Also there is an Ikea group online -google IKEAFANS, very wide knowledge base there.
If you go with toggle bolts keep in mind they have weight ranges in the package and you may need a flat washer under the machine screw head to hold the ikea metal piece tha engages the hanger.
I did a Varde kitchen recently, and a bath with a bunch of funny names beginning with V
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For those following this discussion the recommended website is http://www.ikeafans.com
-Jason

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