If you just want to guard against month to month spikes, you could head over to MPOE
http://polimedia.us/bitcoin/options.php and buy call options - he's offering 1,2,3 month maturities. The ordering system is not simple
Bitcoinica won't work as well as you'd like - the position is a leveraged one in which you never take delivery of actual coin - you'd profit on the rise of coin, but have to buy coin then, costing you at least the difference in the spread at the time of position exit & exchange to BTC. The 10:1 leverage option doesn't allow for the size account you'd need ($2k max)
There might be a few people around who'd talk about options with later maturity dates. If I were going to work out an options contract long term, I'd need guarantees that the counterparty had the coin locked up until the maturity date (i.e. a long term CD with a reputable bitcoin banker)
Because there's so much uncertainty about the long term exchange rate, 3mo options may be all you'd really want - your counterparty's risk on a longer term option would likely increase the premiums too much.
Seems another way to hedge the risk (partially) is by shopping for inexpensive mining contracts/bonds (lol, while still reselling your hash power) If you can pay for this in USD you might have it made
EDIT: but if you have experience trading, it seems that you could do well to start a $2K USD funded account, w/ a long position with minimal initial capital risk, build that position on dips & rallies (as the position show more profit, add on to it, using profit equity as additional risk capital - as long as you limit the risk on the position to say 10% of capital, you can take a lot of downside, which doesn't hurt you too much, and with only a small amount of actual risk, you have little chance of force liquidation. When the account size grows, you'll have to cash some or all of the position out, and go to 5:1 until Bitcoinica has more capital to offer as leverage. The less you touch that trade the better, I'd think

I actually think bitcoinica could work very well for an experience person, using limited risk, and a very long term strategy on a long position. you can't hedge your whole loan this way, but it would help.