Hi Sean,
If you're looking for a decent classic Amiga setup, your best bet is an A1200 + some key extras. Using a CompactFlash card as a HDD is a commonly used strategy for Amigas, something like this is worth considering:
http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=883Would like to ask, what do you intend to use as a monitor? If you want to use a PC VGA monitor, and want a high quality picture, then a device like the Indivision scandoubler/flickerfixer is also worth considering. Unfortunately they seem to be out of stock on Amigakit right now for the AGA version, which is what you'd need for an A1200. You might be able to buy one elsewhere though.
Just curious, why is OS3.9 a requirement for you? Whilst it is the latest version of AmigaOS designed to run on the 68k Amigas, it adds a noticeable amount of overhead when compared to OS3.1 (or even OS3.5), from what I understand. If you're looking for a cheap Amiga, then sticking to OS3.1 may save you from wanting to get an accelerator.
