Probably the most important thing is to make sure that if you're holding for the long term as a hedge, that the interest rate calculations used for calculating position financing are as 'pure' as possible. I hedged a cable position last year for about six months, and when I looked into it, relatively few brokers applied the financing rate without some kind of adjustment in their favour (ie deducting debit interest, but not adding credit interest if applicable, or adding/subtracting a few hundred basis points from the debit/credit interest calculation). Getting this right will make a much bigger difference than a pip here or there on the spread. In the end, I went with CMC who at the time offered what I was looking for.
Which instrument? One missing from your list are CME forex futures - they do a Euro mini-contract worth EUR62,500 although this might be a bit big for your purposes, it's worth looking at. The choice then is between FX and spreadbetting, and as you're hedging I would go for the one that is on the same tax basis as the positions you are hedging. Sounds like you're trading on a taxable basis, so I would go for FX, that way any loss made on the hedge can be set off against capital gains in your trading. In practical terms, there's not much difference between spreadbetting and FX if you're just holding as a hedge and as long as the interest rate is correctly applied.
