Congratulations! I too had the bug to build an A1200 system. I am replacing the Ami that had been stolen so many years ago.
I can easily recommend amigakit for the EZ-Z4 tower, vesalia.de for my Amiga1200 NTSC mobo, IDEtoCF adapter for my hard drive that I got on eBay, though I think I later found one on amigakit or vesalia. As for my floppy I found an adapter from Australia
http://www.ianstedman.co.uk/Sales/sales.html that when combined with a PC floppy and Amiga floppy cable it actually works like a charm. Even clicks when no disk is inserted!
What memories...
A good way to get the OS is to get AmigaForever. That way you can replicate the Amiga OS3.1 install disks.
Also, there are 030 accelerators available which can spped things up. I currently have a ram expansion + FPU while I save up for a speedup card.
BTW, the same australian place I purchased the ATX to Amiga adapter that I use in my tower. If you connect the case power on lead you can turn everything on. Otherwise you would have to get an adapter cable with a loop and switch the main PS on/off in the back.
You mentioned getting your Ami on the NET. I think I read somewhere that if you were using a PCMCIA card that it conflicted with memory cards over 4MB? I have one but havent had time to check if this is true. You would need Miami or Genesis, one of which is available on Amiga OS3.9 CD.
Let me know if you have any questions as I might could help as I've been there...
AmigaNow
