Can anybody advise me on which handplane to buy?

I intend to use the plane to do a number of jobs from converting sawn
timber to smoothing finished work.

I currently have an old Stanley #4 1/2, and find it a bit small for
even smoothing work.

Unfortunately my budget will only stretch to one decent handplane, so
i'm torn between a Veritas #6 or Clifton #5 1/2, or even a Lie
Nielson #5 1/2 if I can keep the reciept away from the wife.

For some reason Veritas don't make a #5 or #5 1/2, so I'm wandering
whether the #6 will be too big and heavy to use for long periods.

Any comments would be helpfull.

Thanks

Aled