Native plugins or hardware effect processors?

[ipaqlinux48]

Hi,

In the near future, I must have some plugins especially needed for mastering my songs. I can do three things:
1. Buy some native plugins
2. Buy a DSP expansion board with some good quality plugins (TC PoCo, Mackie UAD-1, ...)
3. Or buy a dedicated processor (TC Electronics, Behringer, ...)

Now, because my PC must handle a lot of things, only solution 2 or 3 are on the menu. But I've a problem with the 2nd solution. A dedicated hardware processor lasts forever (until it is broken), but a software-only solutions lasts until the company decides to stop writing plugins. Suppose, five year later, when the 64 bit PC's are just as normal as 32 bit PC's are now. Microsoft will bring out a new 64 bit OS. OK, I must upgrade to a newer Cubase version, but will there also be a port of the TC PoCo, or Mackie UAD-1? I'm afraid that a software only solution is a short-term investment (5 years). Certainly now that the 64-bit era is waiting in front of our doors.

How do you guys think about it? Should I better invest in a hardware solution or not?