Advice Requested (kind of long...)

With all this in mind, and considering I have numerous retired systems available, I'm looking for suggestions on which platform to use for which purpose. Here is what I have active now: SPARC IPC (Local DNS, intranet only). SPARCClassic, 32MB RAM, 1 gig disk -- Web server. Here are the machines I have available that have yet to be put to use. --SPARC IPX with the Weitek PowerSPARC upgrade CPU, 32MB RAM. --At least one, possibly two more SPARCClassics, 32MB RAM each (both under consideration for mail servers). --NEC RISCServer 2200, dual CPUs, 64MB RAM (Under consideration for taking over as web server at a future point). --Two MicroVAX 3's, 32MB RAM each. --DEC 3000/600 Alpha system, 128MB RAM (under consideration as a future workstation). --VAXServer 3100, 16MB RAM (can possibly go to 24). --VAXStation 3100/M38, 16MB RAM (can possibly go to 24). --ApplicationDEC dual-CPU 486 system, 16MB RAM. --DEC 5000/200 MIPS box, RAM unknown. --Motorola MVME147 tower system, RAM unknown (at least 8, possibly 16MB), under consideration for the "maintenance" node mentioned earlier.