For another 100-150 you could get the HDS-5 and down the road add side scan as well. As well as be able to network another HDS if you choose.
And if you get the HDS5 plus an LSS-2(side scan) soon(purchase between 2/14/13-4/7/13)both have to be purchased in that time frame. You can get a $300.00 rebate which should bring price for both to $1000.00 - $1100.00 or so.