Wanted: Campagnolo Cranks or Chainset?

seem fairly decent for the price (the cranks that is)

are they much heavy? and can you simply remove the smaller chainring without any trouble and use it as a single chainring with the same bolts?

they're not too heavy, can't see much difference (other than the name!) with higher end stuff (though obviously there are some benefits of £££!). You can't just remove the inner ring for two reasons:
1) the outer ring is pinned and ramped (and tin) so I would not want to use it for single speed let alone fixed
2) the chainring bolts will be too long when you have removed a ring - you need single ring specific one (around a fiver a set new)