In all honesty I think you are wasting your time and money.
I didn't check out the Thinkpad but the Compaq maxes out at what 320MB ?
Even if you go for a distro with a lightweight desktop environment you still probably want to run a modern browser etc, that laptop is still last century's technology and to be honest needs to go in the bin.
Another problem with these machines is that nobody is testing the modern distros against them because they are so old they are off the radar now, so you have to expect issues with buggy ACPI etc as the foo that made that machine work might have fallen out of the kernel and nobody cared. At least with modern hardware there is a high chance that someone else has tried to run the same distro on the same machine and reported bugs etc.
I mean I know you said you have very limited funds to work with..but what you have spent on that umax plus buying either of these and did you buy the original thinkpads ? You wouldn't be that far off from a 2nd hand Netbook or sommin else a bit more recent. I mean even if you are managing to stuff what doesn't work back on ebay and sell for what you paid you are still losing postage costs and sellers fees no ?
I don't mean to sound overly negative here, but I just can't stand seeing someone with limited funds waste more money. I'd say try to save up £100 and see what that gets you...If you dump what you have so far back on ebay you might get halfway there.