assessing if multi-threaded server suitable for Weblogic & BEA & Oracle DB : eg Sun T vs M series

My understanding from Sun rep is that :

a) Sun T series (eg T5120) is suitable for webserver app or situation where the
    there's a lot of processes running concurrently & each of the processes (or
    thread or ?) requires little CPU load

b) Sun M series are more for situation where there's little processes but each of
    the process require a lot of heavy serial processing.  So if it's a DB server which
    usually receives a few heavy queries to the DB, then M series is suited for this

Questions :

1) if I have a Weblogic server, which type of server is more suitable, T or M series?
    Weblogic is on Linux & HP-UX

2) any specific commands or tools that I can use to assess my database (Oracle)
    server to evaluate if I'm getting a few heavy serialized queries/load (which M series
   is more suited for) or plenty of tiny little transactions on the DB (which T series is
   more suited for) ?   DB servers are on HP-UX PA-RISC