Because you want to run games, I would advice an 68030. A Blizzard 68030/IV with SCSI-card would be perfect for this. If you want more speed, an 68060 card is (much) better, but less compatible compared to an 68030-card. With a Blizzard 68060, you can use the same SCSI-card as for the 68030, giving you great expandability.
If you're planning to do some websurfing, be ready for a rather, ehm, new experience... You need every drop of speed you can get for it, both through updating your hardware and tweaking the software. If you're only using AGA (and you will, if you're not towerizing your A1200), it will be horrendously slow. Apart from the speedissue, Amigabrowsers have a hard time of displaying websites correctly, apart from the most basic webpages. Aminet & Google work fine, but don't expect it to replace a normal Windows-, Linux- or OSX-browser.
