I am trying to figure out the best way to get my A2000 a boost in speed. I want to add the following soon to it when I get some play money (and listed by my current priority):
1. Indivision ECS. the monitor I got from runequester is starting to not hold brightness/contrast, so it would be nice for to have other viewing options.
2. MiniMegi - who doesn't need 2M chip ram? 
3. Accelerator goes here, because otherwise:
4. Can't use Deneb (AFAIK) on a stock 68000
I find the 030 accelerators in the 25Mhz range more frequently than the ones I would like. Also there are a couple of designs to choose from (ones that plugin to the processor slot, ones that plug into a zorro slot etc.)
Depending on your end goals, an 030 is not a bad way to go at all. Very compatible software-wise and you can find them for less than a farm

Sad to hear about the monitor.
If you got a spare hundred bucks, this works great
http://www.ambery.com/rgbcgatovgac.htmlthough its not significantly cheaper than the Indivision ECS and those appear to still be in stock.
From what I gather, the indivision may give a sharper image than an external scan doubler, but I've also seen a fair number of people have a hard time with them.