I used an A1200 with an 030, and 8MB of RAM. (plus Hard disk, natch!) doable, but a bit cramped - I had to run everything on the WB to save Chipram for images. of course, I could only run IBrowse and YAM seperately - the machine ground to a halt otherwise !
its not so much the CPU horsepower (though that helps with JPEG decoding), but you will need RAM - the more the better ! if you get the 060 you should be Ok.
FBlit is good, as mentioned before. not tried the other one. it also helps to tweak the screenmode as compromise between number of colours, and speed, but dont use anything less that DBlPAL/NTSC - Super72 is recommended if you use one of the smoother versions on Aminet - I even had a hack to run AGA in 1024x768 on my Mikrovitek 1438S, but it was a bit flickery, and quite a ChipRAM hog!