I don't think it's crazy - I'm in the exact same situation, have returned to the Amiga after quite a few dull PC/linux years.
I'm looking at getting another A1200 too, as I gave away all my Amigas years ago and reeally wish I hadn't. A1200s are fun to tinker with if you like that kind of thing. IMO a 030 with some extra RAM is a must, it's a vast improvement over the 000/020 and things like NewIcons (if you want a fancy WB) will be much more enjoyable, as well as general operations and games.
Couldn't say regarding noticable speed difference between 030/060 though, never had a 060, but 030s seem far more common than 060s on ebay. I've seen A1200s with 030s go for around 120 GBP or so on there, so it might be worth hanging on until you see a good deal if you're unsure.
Edit: 3 other people replied while my connection was lagging, so sorry for repetition
