Overpay by -- $1000 at most? For a computer you'll use for -- let's say -- 3 years, or 1000 days? $1 per day? Time is expensive, money is cheap.
I suspect we're not going to make much progress on the Windows vs. Mac vs Linux question because it's too hard. Why don't we start by deciding something easier like Christianity vs. Judaism vs. Islam?
I've now had Win7/Ult on my 8 core xeon system for more than a week. I've found it very fast, elegant and easy to use. Compared to Ubuntu 8.04/x64 Win7 is significantly more efficient at running Java applications. Win7 uses about 66% of memory taken on Ubuntu 8.04 for the same java programs. I realize this is probably due to Linux's excessive stack size, but for me it's simply a huge plus. If everything continue to go well, I'll move my main trading servers to Win7/64 in a few months.
1) not sure of the 32-bit emulator, although I have heard talk that it exists 2) not sure whether trading applications that use support and secondary applications (netframe architecture in particular; data manager applications; quote parsing engines; etc.) not sure whether they are not scaleable to 64-bit, whilest the actual charting applications just might be 3) most trading software almost refuse to recompile and provide conditional 64-bit executables along with their 32-bit baseline executables almost seems too intimidating to those not familiar with programming or support issues in a word, general lack of support of 32-bit emulation
You can set thread stack size in Java. And there is also a system call to set stack size in Linux. I'd investigate this stuff first. I'd also really look into reported memory useage - how shared objects are accounted for might be interesting.