I've just gone the worktop route myself in my "new" office.
3m long worktop, was originally 900deep so I cut it to about 750 deep.
batten along the back wall and one side.
going to fit a leg at the other end once carpet has been fitted.
I then used a couple of 45 degree "legs" in the middle to help support the weight.
I've had a lot of desks over the last 15 years and this is by far my favourite.