I agree that using a zif drive is the easy way to go and more ssd's are available for a reasonable price these days.
But having said that...

there is always another option...
I have been looking into using a micro-sata ssd because it is cheaper. Problem is/was finding a suitable sata to zif adapter.
Two attempts have been made so far and the first one is very hard to do because it involves replacing the zif connector on the adapter. The second one is easier because you only need to worry about the height.
Downside with both adapters is that the UX will run udma2 after booting.
This can then be corrected with hdparm and the baredit procedure if you need the higher sequential read/writes.
Udma2 gives seq. read/write 32/31 and 4K blocks 11/6. forced to udma5 you get 83/56 and 14/6. At udma2 this solution is still much faster than the original harddrive.
Price for a fast 128gb microsata ssd can be as low as 180 US$, 256GB 380 US$. The adapter used in the second attempt was 15 US$. Do the math...
Yes, you do need some soldering skills and some tools, but the reward is not just in the money saved, it is also in the satisfaction you get from making things work.
For this setup i used the Samsung Thin microsata ssd, because after removing the sataconnector you have a drive that is only 3mm thick. This leaves enough room for a modified sata2zif adapter. So be carefull about choosing the sata-ssd that you will use!
Only question left is the powerconsumption, test shows it is equal to the Mtron 32GB.