Although a 030 would be fantastic, it would add extra work and cost to a project like this, and honestly even FastRAM doubles the speed of those vector games. Gunship 2000 is really smooth on my CD32 with a SX32 and 8MB RAM for example, and DOOM runs as smoothly as it does on my A1200 with 030/28Mhz because of the Akiko combination.
I wouldn't say no to a 030, but I'd still gladly buy a new 8MB RAM expansion for the CD32, especially if it also has IDE and Clockports.
If it has 44pin IDE for example you can just stick a cheap IDE-CF adapter on a ribbon with a 8GB CF card on it. Then you can use some software to transfer your CD32 save games from the NVRAM to a drawer on the CF card, backing them up so you can clear the NVRAM for more save games. Then it's just a matter of swapping the save game files back and forth when you need them, from Workbench. It's not a perfect solution but it'll do.
Actually even without IDE, you can still link your CD32 to an Amiga or a PC via a Serial null-modem cable to transfer save games back and forth.
As for Theme Park you can now run the full AGA version from the CF card. You may even be able to run the Mac version in glorious high resolution! I'd like to test this and get back to you, it may run in 8MB but of course won't move around very smoothly compared to the native version.