Mac Mini's are great. That's what I think of them!
Regarding the memory, I would think 8G would be enough, but I guess it depends on how many applications you're running. My system has 4G, but all I do is web browsing, news checking with video with Safari, mail, just typical stuff. I don't do anything like advanced video or mass photo editing that's notorious for eating memory.
Regarding the SSD, you might find the following post interesting:
https://forums.macrumors.com/showthread.php?p=20130380#post20130380
I think the OP had sort of a one-off problem, but problems do happen with them. If you scroll down in that post another guy using ID FrtzPeter talks about a new high speed drive from Hitachi. I went out and bought one after seeing that because it was only about 60 bucks locally. It's fast. It's not SSD fast, but it makes old drives look like molasses.
I had an SSD in my system but got one with 128G, and it was too small. If you're running Mavericks or Yosemite, it really isn't enough. My base folder isn't that big, but I ended up continually needing to off load stuff to a backup drive. It reminded me more of the old days when people had to keep backing up stuff to floppies to manage a small drive and even though an SSD is fast, if it isn't big enough, you'll suffer. It was annoying. The bare minimum size for an SSD using Mavericks or Yosemite is, in my opinion, 256G or bigger.
With SSDs I'd steer clear of Crucial. They seem to have a history of problems higher than anyone else. I'd use the same brands Apple uses, not a one-off brand.
If you go the SSD route, make sure you keep and maintain backups to an old style HD for safety. Some SSDs have been known to just lose all information for some reason. I know that was a common problem some time ago, but backups ought to be maintained anyway.
Everything I'm saying is opinion, so take it accordingly, and congratulations on your purchase. I think you'll be quite happy.
