...questions...
If you *like* Amiga, chances are high you will actually *love* MorphOS.
If you're currently rather short on cash I would also recomment to try out MorphOS on an eMac (note though, that only the 1.25 GHZ eMac models are supportet yet). They are changing hands for really little mony (at least for 50 US$ you should be able to find one with a little patience on searching). If you then disover you actually like MorphOS you are either done w/o big costs or you can decide then to resell the eMac again (for a probably similar amount) and grab a mini (and b4 someone asks, I am *definitely* not selling mine ;-) ) for a little more.
The eMacs offer really a lot for the money, but the CRTs are debatable. A CRT does not only have disadvantages, but I wouldn't like to change back from my IPS-panel and PVA-panel to CRT again.
About RAM: Usually you're good off with 256 MB already, 512 MB is very convenient, 1 GB (or more) is really plenty and rather luxury. 128 MB, like with Efika 5200B, is rather a little too few (works, but shouln't squander with RAM consuming apps then).