Check out Classic Workbench:
http://classicwb.abime.net/
It contains all you need to get the most out of your Amiga, enhancements, programs, etc and is ready for WHDLoad Games/Demos to be added with some launchers.
There is a Classic Workbench pack suitable for virtually every Amiga!
You will want a means to transfer files from PC to Amiga & Amiga to PC, either a PCMCIA CF adapter or networking kit would be ideal, Classic Workbench had the PCMCIA CF drivers so you can just grab an el cheapo adapter from eBay:
http://www.ebay.co.uk/itm/CF-compact...item2c674a14c0
You can get them from China half the price if you don't mind waiting 2-3 weeks...
If you don't have any Fast Ram you might want to invest in one of the new ACA1220/1232's (available from
Amigakit) or just a bog standard 4mb Trapdoor Ram which is sufficient for WHDLoad.
If you want to keep the hardware classic you can't go wrong with the Blizzard 1230MkIV
For the time being if the budget doesn't stretch to the Ram/CPU upgrade you can use the PCMCIA adapter to transfer ADF's to real Disks to play. Classic Workbench has TSGui included for writing the images back.
Oh and have fun & enjoy your new A1200