If you want a faster CPU and more RAM then add this (delivery in September):
http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=43&products_id=1013
I agree with Darrin on the 1200. It can run the full range of classic software unlike the ESC/OCS machines.
I would not wait for the ACA accelerator. I'd look for a used 030 or better to pop up on amibay or ebay or here. You might find use for the FPU or MMU which the ACA lacks. I believe the 68EC030 lacks MMU anyway, correct me if I'm wrong. I guess the main selling point of that accelerator is memory speed and rekick feature and that its new.
If you do start serious expanding on the A1200, I'd suggest you get a beefier PS.
I have a 1200 with subway, wireless pcmcia, 030/40mhz 64mb, SSD, and when I tried to add SVIDEO adapter that put my stock PS over the edge(would not boot). That gives you an idea what you can run off the stock.
I have the APOWER from here:
http://a4000t.comI don't understand why he only has the CD32 one listed. interesting. You can always make one from ATX or micro ATX or I have heard an A500 PS can work. maybe contact him.
this is the thread with the compatible monitors:
http://www.amiga.org/forums/showthread.php?t=58860as far as books, you should buy used ones
I have a external ESATA BluRay hooked to my A1200. That its a pretty inexpensive option. You just need 4xIDE adapter and a compatible IDE->SATA converter. Pretty cool having a A1200 with 4usb ports and a ESATA port

I use these tiny speakers and they are excellent for the size and I don't even like bose crap. They are not excellent for the price though
http://www.bose.com/controller?url=/shop_online/digital_music_systems/computer_speakers/music_monitor/index.jspI got them free for making all of my purchases on American Express. I wonder if they still have them in their catalog.