Welcome back to the world of Amigas. A1200s are the best, but unfortunately RAM and accelerator cards still demand a hefty price.
I browse the web with my A1200 030 in 1024x768 AGA, no sweat. An Indivision AGA helps though, by adding the VGA port and removing flicker.
I've got the same network card, and I've been using it for a while now, it's pretty cool. We just got another one for my girlfriend who has an A1200 with a RAM/FPU card (no accelerated CPU) so we'll see how well it goes on the net with the old 020 and 8MB RAM Max (although only 5.5MB is usable when the PCMCIA slot is in use). Everything should work fine, just a little slow, but stick to a 16 colour Workbench and don't open too many tabs in IBrowse at a time and you shouldn't run out of RAM too fast.
We've got IRC, MSN, AIM and Yahoo compatible chat programs which are pretty neat, and allow us to stay in contact with the rest of the world from our Amigas.
Other than the Indivision AGA,, another bit of hardware I've really enjoyed lately is my Subway USB card. It's a tiny little thing that also fits inside your A1200 case and provides four USB 2.0 ports, which are fully compatible with mice, keyboards, flash cards, hubs, external HDs, rocket launchers, printers, digital cameras, and those cool Media Station things that look like mini external hard drives, but they play MP3s, DivX AVIs, MPEG, JPEG, WMV and all those modern video/audio formats, so your A1200 doesn't have to do any of the work to play all those movies and albums you download from Kazaa, Limewire, Bittorrent and other P2P protocols (all available for your Amiga 1200). Just make sure your monitor has dual-inputs (1084S or most modern VGA monitors for example).
GMail works through YAM (and most other Amiga email programs) as well as IBrowse, no problems.
Have you used mouse gestures before, perhaps in Opera or Firefox? There's an awesome application called Meridian that allows you to add mouse gestures (as simple or complex as you want) to any application or Workbench window or screen.
Perhaps you like to play a game on your desktop while you're bored on the internet. There's the excellent Change It!, a skinnable Bejeweled clone, WBsteroids, the resizable Asteroids, plenty of card games, Mine Sweeper, Tetris and Arkanoid clones too. There are a few cool Workbench games you can play over the internet against other Amiga players as well, like Dynamite, the configurable, skinnable Bomberman clone, or how about a game of Monopoly?
Get yourself an 030, and you can play a classic multiplayer game of DOOM with us. Heck, it even runs on the 020 with some Fast RAM if you can handle a smaller play area.
If you want to make sure all those KGLoad and WHDLoad games work perfectly, you have to register WHDLoad at
http://www.whdload.de This piece of software is actively developed by several dedicated, hard working Amiga enthusiasts and they deserve our support for allowing thousands of classic games to be run directly from our hard drives, either through Workbench or from games menus like KGLoad or Advanced Menu System.
If you haven't got one already, try and get a control pad to play your games with. Any Sega Master System or Genesis pad will work (Buttons 1&2 or B&C) for games supporting 1 or 2 buttons, or get a full CD32 compatible pad. There are a few options, an original Commodore CD32 pad, a new Boomerang CD32 pad from AmigaKit, or a rare Competition Pro CD32 pad which are getting hard to find at a reasonable price. Hopefully soon there will be more Playstation-CD32 adapters or USB adapters on the market. You can also get a PC gamepad-Amiga adapter.
Make sure you download a good MOD player and plenty of mods to listen to, there's a WIDE variety out there to go through to find something that suits your tastes. Check out some Amiga demo websites to find some great demos that should run on your system too, they'll really show what your hardware is capable of.
Enjoy your Amiga, now that you have the room for it you have years of potential fun ahead of you, including NEW games developed for your 18 year old system. Fancy an Amiga-style Guitar Hero clone? Tracker Hero is coming out for all AGA Amigas, and it'll support PS2 guitars as well! There are also a few action games like Annihilation and Halloween Nightmare still in the works.