> So can I still do office work(VB stuffs, office Xp, DB2
> server) under MOS?
If you need to run PC software. Then you can do most (non-networking) stuff with the aid of BOCHS. But it'll harken you back to the days of 486's (not sound and networking though). If you need to run DOS software then DOSBox might be able to help you and it's slightly faster (maybe by the virtue of not having all of windows bogging you down.)
If you need to run MS Office, then you might be able to get away with PegXMac + MacOSX + Mac version of office (and other software that is available).
That said, I pretty much don't bother with most of that when I'm at home.

I use my Peg+MOS as my main system but I generally only use it for general web browsing, e-mail. I use VIM to edit html and write Hollywood scripts. I do graphic work/image processing with FxPaint, ImageFx, Cinema4D and Drawstudio 2. When I need to write a nice document, I generally just go into Pagestream and save it out as a PDF for distribution.
I occasionally hop onto my low-spec (Pentium 500 Celeron) laptop for things that are only available on the PC... But that's generally not too often.
Personally I would be overjoyed if there was a JAVA virtual machine but I'm not counting on it. :-(
If you are strictly looking to play games, then in most cases you'll be stuck using UAE for MOS (unless they are later games that are system friendly). The only edge MOS gives you over PC UAE is it's compatibility with Amiga PPC software. And with PearPC, it might no longer be that much of an advantage in the future.

The safe solution for you, would be to go for a PC + UAE solution especially if you're just looking at using your current software and not looking at another OS upgrade. I would recommend having a catweasel mk III as well. (It greatly simplified things for me with my Pegasos.

)
Sadly, there are better solutions to run Amiga software on PC's, then PC software on Amiga-based solutions.