A few questions regarding Acer Aspire One hardware upgrades/mods

So, I got myself an Acer Aspire One ZG5 with 8Gb SSD ans 512 Mb of RAM. I love this machine, but have a few queries.... It came with Linpus Lite which seemed capable, but I am used to Ubuntu and among other things like to play OpenTTD, which seems not to run on Linpus, so I installed Ubuntu Netbook Edition and love it.

I have a few queries, though. With Linpus and Windows XP, it appears that I can install an SD card in my "Storage Expansion" slot and have it appear as extra hard drive space. This would be ideal as frankly 8Gb is barely enough for an Ubuntu install with software as when streaming video and browsing my /tmp folder often increases to 1Gb. I often get messages advising that I have under 350Mb left on my Hard Drive. Is this possible with Ubuntu Netbook Edition, and if so, how?

Also, I have got a spare 1Gb RAM chip for this machine that I will be installing shortly. If it is not possible to set up my machine to use an SD card as a storage expansion, I would be inclined to replace the 8Gb SSD with another drive at the same time as the memory upgrade, given the extent to which I need to strip this machine down to achieve either upgrade (rather than simply removing the back panel,I'm required to remove the keyboard and wrist rest, then the backing plate beneath it, before removing the motherboard, as the upgrade slot is on the underside of the motherboard. Is this possible, and if so, does anyone know where I can acquire a compatible SSD for my machine? I know very little about these drives, and from a little googling it would appear that these drives range enormously in price (£30-£800) and performance. Does anyone know what if any drives are compatible with this machine, and where I can pick up a drive which represents good value for money, preferably in the UK?

I hope that someone may be able to provide answers to these questions, but if no one knows an exact answer, I'd be grateful simply for links to websites/ blogs or any other resource that may be of assistance. Thanks in advance everybody.