Creating a restore partition without DVD?

I´ve just bought an Acer Aspire 181OTZ netbook with WIN7 from a private seller, to use during our extensive travels as a travel computer. There is no WIN7 DVD , according to the seller there never was - it had a rescue partition, but that partition got erased (erroneously according to the seller) when the seller "nullified" the entire HDD before selling the netbook. The netbook is out of guarentee, so no way to get help from the maker.

Is there any chance of creating a rescue partition without a WIN7 DVD or is my only option to make an ISO image of the system on a USB stick? Obviously, ISO on DVD discs is out of the question. An ISO on a USB stick would require a 32GB stick, (plus another USB stick for WIN PE), so I´d prefer to create a rescue partition if such a possibility exists.

Well, doing an image was my thought, however, this Acer will be used during our extensive travel, so I´d have to carry with me either an external USB connected HDD (plus one USB stick to boot the WIN PE) or two USB sticks, one with 32GB at least to have enough space for the image. A system crash has (luckily) never occured to me on my previous netbook during our travel, but I´ve met out there quite a few travellers who had a system crash and no rescue partition available on the laptops/netbooks. It seems I have no option but to go for the image and carry 2 USB sticks with me just in case WIN7 goes down while I´m away.